BOP_Craig

I am still a ways off (at least a year) from being in a position to even begin seriously considering having an engine built, so take my comments for what they are worth (not much). However, for my goals I would think the 3.875" stroke would be fine when it comes time....

Mark, I know you listed prices for the kits, how do they compare to the cost of having a 330 or 350 crank offset ground (for a 374 stroker) and acquiring the various other parts included in your kits; the bearings, pistons and rings, and the rods?

Also, are these cranks drilled for a pilot bearing for a manual transmission?

cutlassefi

Thanks Dave, appreciate the input.
As it turns out, I may have the piston issue worked out anyway. Again thanks.

Professur

Ok, stupid question, but that's my favorite kind. What kind of numbers would we get putting this into a '81 307?

oldsmobiledave

Swapping a 4.00" stroke crank into a 307 raises the cid to 363 cid with a standard bore. Run a 0.030" overbore & you now have 369 cid.

Professur

That almost makes it worth trying.

oldsmobiledave

No...it doesn't.

cjsdad

I think Dave is trying to tell you that it would be easier and a lot more economical to swap in a 350. It looks the same from the outside and those 13/19 cubic inches won't make it worth the extra cost.

cutlassefi

Cost would be about another $1200-$1500 over a "stroker" 330 crank combination.
However that's apples to oranges. This crank is head and shoulders above anything else out there short of a billet.
Plus you can't get the same cubes with the 330 combo, not even close. And as everyone knows, there's no substitute for cubic inches.
And I wouldn't do it in a 307 mainly because of the windowed blocks. I'm sure that's what Dave was referring to.

cjsdad

If my math is right though a .030 over 330 with a 4 inch stroke almost makes a 396. 395.7 to be exact. That could be fun but still probably more economical to go with a 403. Most of us probably won't benefit from all of the go-faster goodies that Mark comes up with unless you are building a serious street/strip or strip only car. It is fun to think about though.

cutlassefi

Hmmm I have to disagree. Why not a big cube, 8.5-9.0:1 small block that’ll run on regular fuel and still be a stump puller, WITHOUT the weight and hassle of a big block? Hmmmm

cjsdad

Oh, don't misunderstand. I would absolutely LOVE to have a stroked engine like you are creating. More than double the horsepower from my little 330 in the exact same package with good street manners is a dream come true. I may even try it if I can come up with the spare change, but for the average guy that just wants better than average throttle response in a cruiser it is a lot more expense than a typical rebuild with a nice cam.

Could you maybe give a parts list required for the average guy that can have his own crank ground offset and then apply your parts?

Crank dimensions
rods
pistons
rings
bearings
roller cam/flat tappet cam
intake
carb

That kinda stuff. A complete package that a guy can order the parts and install, or have his engine shop order from you and assemble a long block.

BOP_Craig

Thanks. I knew there was several reasons it couldn't be a straight comparison. I hadn't seen a dollar figure to do the offset ground and I was curious to see what the difference would be. Certainly there is truth in the statement that there is no substitute for cubic inches... The question, in my case anyway, is do I need those extra cubic inches.

While I haven't settled on anything yet, I am starting to lean toward something along those lines.

olds 307 and 403

If someone has an 80's Hurst/Olds or 442 this makes big cubes easy in a stock looking package. Of that still leaves 5A and 7A heads to deal with.

oldsmobiledave

A stroker small block is a great alternative for the 1979 HO & 1980 442 owners as well as any of the 307 powered G body cars. Also entirely applicable for the 1973-1977 Colonnade owners who's cars are far more likely to have come with a 350 than a 455.

cutlassefi

You’re right Dave, IMO that’s actually the best place for this type of build.
A lot of guys are still racing and driving G body’s, and while you can put a big block in one, it’s a bit of a hassle.
I’ve ordered the next batch of cranks, all 4.00” stroke. It seems most want the most c.i. possible. Plus I may be able to arrange a deal on a competitively priced piston from Mahle, we’ll see.

Professur

Ah, but what you guys are missing is that, in some places, changing your block to one that didn't come as factory means you now loose that grandfathered status where emissions are concerned. Ontario being one. I'd love to drop a nice 455 into my '81 CC, but since that wasn't an engine that came in this car that year, if I get pulled for inspection driving up the 401, I'm screwed. And I've heard reports of that happening. Granted, those were dropping in obviously new LS engines, but with my luck, I'd get that one guy who knows Olds engines. I don't see anyone making a 455 pull off new emissions spec

oddball

Mark, what about pistons in the 4.375" neighborhood?

cutlassefi

Custom, but not a problem. About $800.00 a set with rings last I checked.

mikejana

Okay, Here we go, I'm in!
https://classicoldsmobile.com/forums...t-350-a-2.html

cjsdad

That is gonna be very cool. 422 cid is almost close enough for you to tell people you have a small block 425!

oldsfromyell

What piston did you choose for your 434 stroker that you posted pictures of? Is it the SRP professional series or Mahle? Thanks

cutlassefi

oldsfromyell

Awesome news. I have been looking at piston options for the engine I am piecing together. Are you having to do them in batches of 5 sets like the other pistons you are having made? If you would can you send me a email(oldsfromyell@gmail.com) or message on here with information and ordering details on the pistons you are getting made for the 4" stroke combinations. Thanks

cutlassefi

Emailed you.

babailey

Subscribing

87442efi

Sorry that I am late to the discussion, I just found this topic on FB.
I just built a stout 355 so, pushing 415 hp in my 87 442. But hold on, it is not enough, so
I am preparing to build a DX block this fall.
These crank kits your selling will they work in a DX Build or just the gas sbo.
I would like to make some good torque over the HP numbers after all torque gets ya moving.
plan on running a true 10.5 to 1 like the 68 olds ran.
am following and very interested in purchasing a kit.

olds 307 and 403

Was the 355 dynoed? That is a very strong 350, what are the specs? You will need spacers for the crank, they have been proven for big power in DX blocks. Also the 4 bolt cap conversion is a piece of mind and get a 4340 crank if you really plan on boosting it or big nitrous. Mark won't steer you wrong.

cutlassefi

87442efi

yes it was dynoed. I had Felice Perf. Build the motor.
I wanted a dx build but there was just no time to do it and enjoy the car for the summer so i went with a 350 olds true 10.5 to 1 swapped the #5 heads for a pair of pro comp heads, went with a hydraulic cam, not roller, sharp rockers dont have cam card in front of me but something like 325 339 525 545 I believe were the numbers for the cam. with a Holley sniper fire efi sitting on a Edelbrock 7111 I take. It is in my 87 442. The motor runs great but I still want my 350 DX stroker. I am enjoying this build this summer but this fall I will build my dx motor and let my son have the current motor for his 75 cutlass supreme.

87442efi

no nitrous or boost for me, I am old school, I feel I am cheating by using the sniper efi, but man is there a big difference from the quadjet yo the sniper. I am following and please keep updated.
thank you.

olds 307 and 403

Very nice combo, another positive review for the Holley Sniper.

cutlassefi

olds 307 and 403

Interesting on the 5140 billet. I know there are advantages and maybe draw backs vs a forging. Unless you have a boosted DX or Nascar block, these cranks truly won't see anywhere close to fatigue strength, which is awesome. I know the 330 crank has been quoted to survive up to maybe 800 hp if mostly crack free but they are 50 year old forgings and can't be stroked to 4" and weigh more.

cutlassefi

Just the 422 for Mike "rebuild of my rocket 350". However I have 3 higher hp stroker builds coming up in the next few months.

81sleepinOLDS

After endless internet searches for my Olds 350 block that has been sitting for 5 years, I've finally found it's calling. Although, it will take a bit of time, I can't wait to join you guys in building a stroker Olds. Can't wait to see all of your builds