coppercutlass

If that's the case I'm sure you can find 30 hp from the engine with tuning and doing little things that add up. I started the summer running 13.09's ended up 12.60's. I did some minor things to free up hp and get the car hooking better ( electric water pump , fans and took the sway bar off for track use. And I'm still gonna dig at it. In the past I picked up almost 2 tenths with an x pipe. If its 30 hp you are after I think there is always room for improvement. The op mentioned 400 hp goals that's been done with a 355. No need to stroke it to make those goals happen. That money could be put into something else that will make power.

captjim

All I'll say is that if stroking a 403 was a good idea, there would be more guys doing it to get the extra inches, but they are not. The extra inches is not worth what you have to compromise to get them. IMHO Do a simple 380, easily make 400 HP, and be done with it. Wanting to hit the magic mark of 400 cubes just to say you did it does not make a lot of sense to me.

captjim

Once again, if you do the math, it really is not very much more money. There are little hidden costs like pressing the rods, etc. So, you can have 40 year old re-conned rods with heavy slugs sitting on them or brand new stronger rods on floating pins with lighter, modern pistons and rings, plus the extra cubic inches, for only a few hundred dollars more. The extra power those extra inches cost is a VERY cost-effective decision, IMO.

coppercutlass

I was saying just run a 403 with forged slugs. No stroke. The rods and pistons and offset grinding the crank will add up. I don't see it as a minor cost. My current bottom end cost me 2k. It was a swap meet build but it was a wash as the rotating assembly was not balanced and I hd to scrap the block and use one I had. Will a stroker cost this much. I'm just trying to be realistic here. What does a short block stroked build run with cam and all that stuff.

Bernhard

It would be interesting to price all build options

DX

403


355 cu
380 cu stroked

455
455 stroked

Then weigh all the pros and cons

captjim

Can you make a single post without talking about your own stuff? Who builds a quality engine and does not spend the $ to balance it??

OK, maybe Mark will chime in since I keep saying the same thing. What is the ADDED cost of a stroker? One more bore and offset grinding, right? Plus, you need to purchase new rods (which most guys would do anyway if replacements were available for a SBO). Pistons will be a bit more expensive but MUCH better with a better ring pack. SBC bearings can be used, maybe cheaper?? You save the $ to press the pistons off and on and recondition the rods.

So, how much extra is it? Don't forget, you get an automatic 20 ft/lbs of torque for that.

wr1970

I will go on a limb and say the 380 is streetable and yeah $2000 will not get you there! But you will can't tune your motor into 11's which the 380 is capable of.I am not putting down your combo it is a good effort made by YOU! This is what you might look at if you were to want a faster yet not a big buck build.You are a guy who looks for cheap hp and cheap parts this is a good up grade.I know what the op says he wants i just think he should weigh his options better and be open to less than a 400 ci. Then if he wants a 400ci and 400 hp that is all he wants a 403 will get him there but not a motor i would choose.

coppercutlass

Jim my stuff was balanced. My point was I scored the short block at a price I thought was good and hoping it was balanced. I had it balanced. Any way wr1970 I agree I'm after cheap hp. Could I tune my crap to run 11's or close sure but I like a challange so I gave my self restrictions. A comparison would be great cost vs advantage. Jim I mention my stuff because its a real world build with price vs advantage . I'm not just preaching I mean isn't that what most people want is real world results. That's why I always say dyno numbers are bs. Its all about what I actually puts down at the track.

wr1970

Copper i am saying 11's not just 11.90 i am saying all the way to deep 11's depends on parts and budget! Your way of doing it i am sure you could tweak a 380 to 11.70's maybe to mid 11 with min cost and still be streetable. Why because you do your own work! Of course you would have to shop around to collect the parts!JMO

coppercutlass

I guess it comes down to options and prefrence. We all have diffrent views. Can more cubes make more power ., there is no doubt about it yes. But can certain goals be achieved with less cubes ???? That's where I would look at cost and whats the cost vs. Advantage would be what's been done. I know .,not everyone is racing the 1\4 mile but that's real world hp to the wheels at the track. So I would see what others are running ,what wheight what accesories like power steerinf a/c etc etc they have streetability issues. I don't just look at the engine but the whole package .

83hurstguy

Your argument about finding power with accessories and tuning applies to all cubic inch engines.

There's currently a 4.125 block with 3.6 stroke 330 crank on ROP for sale for $675. Seems like a fair deal if the machining was done right.

coppercutlass

Not much of an argument more of a statement to question \see what real world experiences are with stroker builds cost vs hp vs advantage. Guys build or have engines built have the dyno numbers but don't realize it takes power to make all that stuff work and they end up with a slow car once its said and done. Somethings are overlooked. Its all in the details as they say.

wr1970

Yep that looks like a good deal if it was done right!

coppercutlass

Yeah you buy that short block and then but the heads from brownbomber77 and you are wayyyyy ahead of the game. Now that's a build I would be all over if I had the cash. Low initial investment with a lot of potential.

young olds

These

coppercutlass

So if its gonna be a street car why not build a tq. Monster low reving 403 and have 53 more cubic inches vs 30 . People make the 403 to be weak but the truth is its been done. If its tq. And cubes you want then the 403 seems to be more appealing than a 380 stroker. The 403's have their limits but also their use. Id rather spend 1000 bucks adding lower end support to the 403 than 1000 extra bucks to just end up with 30 cubic inches vs the 403's 53 cubic inches. That's just my logic . Bang for the buck vs cost and capability. Not saying the stroker is a bad idea but after what's been mentioned , the use what's expected it seems like the 403 would yeild much more tq.

captjim

It is nowhere near $1,000 more to build a stroker, which will be MUCH stronger than a 403 with a girdle. Also, 409 (403 bored) minus 380 (stroker cubes) is 29, not 53 ci. 403s are not that easy to build correctly.

coppercutlass

I was figuring a stock bore forged piston jim . And I was comparing a stock bore 350 to a 403. And a 380 to a 350 cubic inch wise. So the 403 has 53 cubes on the 350 and the 380 has 30 over the 350 sorry about the confusion. Now the thing to think about is the strength gonna be an issue with its use ???? Like I said many guys have built 403's for the strip with the halo and they live. I know a stroker won't cost 1000 bucks more perhaps 500 more with the work and what not., but you do have 23 cubes over the 380 with a 403 . I know strength is an issue but the limitations have been know for a long time . I get where you are coming from but if its never gonna see high rpms why not build a grunt engine from a 403. I would not hesitate to build a 403 but yet again I won't hesitate to go against the grain .

wr1970

Dr Dan had a 403 build that went 11.83. But i haven't heard of a low 11. second 403 yet! His words a street car!

captjim

Then why did you say so?

coppercutlass

Jim maybe I worded that wrong but I meant I would rather put 1000 bucks into the halo in a 403 that build a 380 fully knowing a stroker would be about 500 bucks or so extra. But if you build a a stock bore 403 you save money on the boring . You might spend let's say 500 more on the halo set up than going stroker but you save 180 not having to bore it and just hone it for forged pistons that means you spent 320 more than a stroked but ended up with 23 more cubes.

80 Rocket

Torque is for semis hauling 40 tons of weight. Horsepower is for guys who want to go fast.

coppercutlass

Lol. Based on current logic don the 355's can't make power. They need more stroke. How did you guys manage low 11's with out it.

80 Rocket

I don't think anyone said that. If they did, it is silly.

However, I'd rather have a 380 over a 403 for that reason.......horsepower.

captjim

Again, you are being a smarty azz and missing the point. For a small increase in cost, why not increase cubic inches, reliability, and power? There are not many places that you can increase torque by 30 ft/lbs and HP by 20 for $500, not to mention a stouter bottom end.

IF a decent SBO replacement rod and decent 350 SBO pistons were readily available, I might agree with you. But, they are not. So, by "stroking" you not only gain the inches, you get far superior parts, more cubes, more TQ and more HP for a minimal investment.

coppercutlass

Jim what I'm saying is the goal is 400 hp that can be done with a 355 all day and be streetable even with a stock rod.

coppercutlass

Don just made my point in what I said earlier in the thread for an hp build I would do a stroker . I feel with what's been done the 403 can handle a certain amount of abuse and I wouldn't hestate to build one with what's been done with them . Guys keep talking about fast on the street well on the street you drive tq.

captjim

That is NOT the subject of this thread. We all know that a 355 can put out 400 HP without a lot of trouble. He wants opinions on a SBO stroker, not a 355.

I quit posting here for quite a while, now I remember why. Adios.

coppercutlass

that's why I said you don't need a stroker to build 400 hp. Its been done with a streetable 355 so a stroker is kind of something I see as unneccessary to build that kind of power that's my opinion about a stroker for something that can be done with no real extra work. He already has a 355 why not build upon that to achieve the goals. I'm sorry that my views on stuff are not what most would agree to but I'll be honest about it. If you want a stroker that's cool but unneccesarry for the goals that have been mentioned.

wr1970

What captjim is getting at is copper you have made this more of your build instead of what the op is asking which is a stroked small block options not a 355. Don already stated he would rather have a 380ci for a reason!! Your combo works good for you we got that. A 380 is much better. Again this is JMO and several agree.

coppercutlass

Don agreed to the 380 for hp. Hp lives in the higher rpms which are never seen on the street . I'm looking at cost but I'm not gonna beat a dead horse . This isn't about my build I used it as an example on how a simple 355 can perform very well and it does not need to be stroked or any special crap to make the goals mentioned happen. I'm sorry but I see it as waste when its not needed for the application . This is what happens when people drink the kool aid. Have you built a stroker??? I mean who here has actually built a stroker ????? Perhaps you have but What I have built is a 355 that when the numbers are plugged in I make 370 hp and according to others I'm leaving hp on the table but I won't sacrifice the streetability and I will find ways to make it faster. We have had many members have stroker builds built with dyno numbers but what about at the track where its actually put to the test ???? I haven't seen so many so I go based of my experiences. If my little basic 355 built with old stuff and hand me downs makes appx 370 hp at the fly based on track numbers and is very comfortable to drive on the street 400 should be easy with a bit of attention in the areas I did not do anything to like porting ,or carb tuning or any major tuning for that matter . So why is a stroker needed ????? When its been proven a street reliable 400 hp 355 can be built ???? That's my point.

wr1970

Yeah he did but you are not loosing anything on the street with a 380ci also! Comes down to prefrence you have yours and others have theirs.

coppercutlass

What is there to loose. What really is the loss. Can you measure on the street the loss between a 380 and 355. You really need all that to go to the dairy queen or the local cruise night. I may have the power on tap but I don't drive the car any diffrent than my daily driver. No need to really.

80 Rocket

Horsepower always wins. If you are just cruising on the street, a 305 chevy will get you from point a to b.

Guys always say they want "torque this" and "torque that". Torque is just a piece of the puzzle, not the end all be all. I want power, not torque (Power= tq x RPM). If I wanted torque, I'd go build a big block.

And if I wanted power out of that big block, well, then its time to shell out some coin so it can spin some RPMs. Otherwise, all you end up with is a stump puller with massive amounts of torque down low....

...and as I mentioned, if that was my goal, I'd go get myself a Peterbuilt and start hauling freight around the countryside. I would communicate via CB all day long and stop at run down truck stops shooing away lot lizards.

So, to the OP of this thread.....I would say this:

If 400hp is your goal, a stroker engine is not needed, but is always good to have. I would build a nice 374 stroker or something like that so as to keep the costs in check. The cost of trying to adapt a 425 crank in a small block would be stupid money for such modest goals.

I'd stroke the 330 crank to 3.5" and bore to 4.125" for good pistons/ring pack and have some fun. A modest port job on some irons will net you well over 400hp with the proper cam and will be completely streetable.

wr1970

I am in agreement with all the above. 374 stroker or 380 who cares it is all about hp on tap and still a streetable combo.

captjim

Not sure that remark was necessary, why go insulting people? It is all opinions, there is no "right or wrong" way. You like doing everything as cheaply as possible, but your way is not the only way.

Here is the deal, you can obviously build a strong 355 using old stock rods, heavy pistons, and crappy rings and make it run. You did it, I have done it, many, many others have as well. You can also spend a few dollars more (around $500 +/-) and have lighter pistons, stronger rods, a MUCH better ring pack and 25 more cubic inches. These upgrades along with extra inches will yield another 30 HP or so as well as being stronger (better rods, lighter pitons) on the bottom end.
Again, neither path is right or wrong, but for you to say it is a "waste" because you are cheap is close-minded, IMO. It is up to each guy to spend his money the way he see's fit. But this whole attitude that Oldsmobile enthusiasts have is one reason that so few products come to market for us. If you think that is BS, ask around to the guys who know. They make a block for Buick and AMC, we can't even get a replacement connecting rod.

coppercutlass

I get your guy's point of view. I have my own twisted ways of doing things . Do we need more aftrmarket stuff yeah we do. Do we have some options yes. We obviously all have diffrent opinions. I'm not cheap for the sake of being cheap but 500 bucks is a big chunk of my mortgage or bills so I not only look at it from a hobby prespective but financial. Are the stock rods the best no but will they hold up ., yes . We do have better options in pistons that the speed pros. Current build I'm working on has the probes they are light compared to the speed pros and have a better ring pack. He already has a 355 why not build upon that ???? All he probably needs is some good head work , a carefully chosen cam for the build and all that good stuff. I can explain my thought process but that's getting way away from the point. You guys ain't wrong and I ain't either because it can be done on both ends goal wise.

oldsmobiledave

Bingo. Winner. Agree 100%.

wr1970

Copper you are being a insulting smart azz! You accuse me of being insulting! Drinking kool aid!! You're the close minded one on this one. Yes i have a stroker engine i built! You already know i am not doing small block builds normally! Do i have a small block build in the wings absolutely mine is a 350 diesel stroker! I will not settle for a 12 sec or a 11 or even a 10 with it! Why challenge me on what i can do or anyone else for that matter? All my engines are track tested.I have built several cars and several engines. There is no need to rehash and be insulting. You are the beginner some what! Some of these other guys are lending experience to this topic you should take that in to account and be a little respectful.JMO

coppercutlass

That came off totally wrong on my end . I want truth in numbers not what can be done or even dyno numbers. By a waste that comment was based on what I would do not what can be done or what's best. I'm not doubting the 380 can make more power. I don't wanna be the fastest that's been done and overdone. I wanna be the fastest withing certain restraints because anyone can throw parts and money at the situation . Can my car go faster with more gear sure it can but I'm gonna do it by other methods to prove a point. That's what I kinda do.