Hello,
After owning my 1979 H/O for 42 years she is getting a transplant. The R code 350 is being replaced with a 425 7.0L from my 1966 Tornado, the engine is now at the machine shop. I would like to have some fun with the car and bracket race her on the weekends, most likely no daily driving anymore. The car has C heads on it (yes they are the originals, I can verify that) and we are staying with the 10.75 ci. I'm looking for advice on cam/lifter/valvetrain/converter/header recommendations. I am also swapping out the 7.5 inch 10 bolt with a Currie enterprises 9" with 3.90 gears. I have an Edelbrock torker intake that will fit under the hood with a 850cfm Holley 4150 DP.
Thanks,
Mike

 

"I would like to have some fun with the car and bracket race her on the weekends, most likely no daily driving anymore." Does this mean it's OK if it's not streetable? Or do you mean a little street driving and some track? Are you willing to do high RPM at highway speeds?

Any idea what kind of ET at the track you are aiming for? Are you willing to lose power brakes, or willing to install HydroBoost to compensate? Also you don't mention transmission, what are you planning to do. I doubt the factory transmission could take the torque of a built 425.

Otherwise sounds like an exciting project. 425s are great motors.

 

Thanks for the reply. I really have no idea about these Olds motors. I've had lots of Oldsmobile cars but never built the motors for performance. I did what a lot of people do; I went BBC and have had more than a few SBC. The point of this car is to keep it Olds power. Its really been a lifelong friend.

To get into the particulars I'm not looking to drive this car on the street. I might take it down to the local hangout around the block from my house, but definitely not on the highway. This is not going to be a commuter car by any stretch of the imagination. It would be nice to possibly drive it occasionally, but not for high speed cruising. I have literally put less than 500 miles on this car in the past 5 years. It just sits in the garage under a car cover, such a waste.

To get the engine under the hood I have to go with a single plane intake, hence the 2730 Torker. Stock this motor had a 800+cfm QJet in the Tornado. I'm going with the 3.90 9" rear end from Currie so that is already bought and paid for. The transmission is still up for debate. I have a BPO 350 as well as the 400. I had a BBC in a 1974 Vega Wagon I bracket raced many years ago. The car went 10.30's and was a lot of fun. That car was Hilborn injected with a 2 speed powerglide. It was 30 years ago so I'm not sure I even remember what the internals were. I know it was 12.5:1 but it wouldn't idle at all. I don't think I want to do that again.
If we could do low to mid 11's with a semi street-able combination that would be a nice goal. I believe this car is around 3400 lbs. and I can run comfortably a 27" tire. I think that puts the HP number with a simple calculator around 480.

 

It can be done. The better the cylinder head is will yield a less aggressive build with same the same performance goal. Best bet is to find a good builder if your unsure.

 

You will need a drop base air cleaner to fit under the hood, it will be very tight, it will probably need a 2" filter. The later A and G bodies were never designed for the tall deck Olds. There is multiple cowl hood available including the VFN W25 style which looks really good and allow more clearance.


You can carefully put the stock hood away along with the numbers matching Olds 350. As said, get a machine shop familiar with the BBO. This sounds like it will be very radical, enjoy!

 

Without any modifications the above is true. I am able to run a RPM air gap and 3-1/2" filter with a Moroso drop base air filter and .312" carburetor spacer gasket. To make this fit I trimmed some of the under hood support structure and lowered the engine 1/2 inch. Stock flat hood.

 

How sweet it is ! You've seen a lot with her.

That's going to be a fun ride, that 425 stock is about double an R code net to net. Tripling the H/Os original power output is going to feel outrageous.

Perfection !

Maniehau, if possible mothball the entire powertrain. I'm figuring you are not using the th350 anyway. A stock 425 would torture it, let alone a worked 425.

 

Before pulling the R code fog it heavily with marine fogging oil and run it out every ounce of gasoline possible. Pull the block drain plugs.

Good luck!!!

 

Here is the patient. I've owned this car since July 1979. She has 102,286 miles on her. The original 350 R code and 350 trans were rebuilt about 5 years ago. Thank you for all of the great advice. I'm hoping to put her in the 11.30's if possible. I will definitely be fogging the motor and putting the original 350/350 combo on the shelf for now.

I'm wondering what trans is best behind a worked over 425? I'm thinking a 3000-3500 stall with the 3.90 gears. Still not sure about the correct valve train to match up with 10.75 ci with C heads. I think the heads are going to be the bottleneck with her.

Thoughts? Suggestions?

Thanks, Mike.

 

There you go, get those motor mounts. There must be an extra inch at least vs the 81-88 hood line, definitely good for a BBO swap. I was very tight with stock mounts, SBO RPM with a 3.5" filter and a 1" drop base in my 88 CSC.

 

Of course low 11s is easily done. I do not like a 9 inch, it robs power. Focus on the drive line, a well done trans with the right converter, its look like your in Arizona from the pictures, I can guide to the right people if your in Az.

120 MPH @ 3500 = 466 HP crankshaft observed HP
1320/120 = 11.00

So a 10.1 comp with a well prepped iron head, a solid lifter cam with a decent oil pan should get it done.

 

Olds 307 and 403 where do I find these motor mounts? I would like to get them coming if possible. Vortecpro, yes I am in Phoenix. I'm all ears on who to get with down here to get this project on the dragstrip.
I don't have to go with the 9" if there are better options. I got the bolt in housing from Currie, but I have another car I can put that in if need be sometime down the line. I'm all ears and looking to learn something.

 

Quick Performance is your best option on a 9 inch

 

66 I just saw your PM. I will give you a call tomorrow sir. Thank you all for the flowing advice and help. This car is a family member and keeping it Olds powered is a big deal to me. I really appreciate all of the help and knowledge.
Mike.

 

I'm curious, what drag strip are you planning on running? Firebird a.k.a. Wild Horse Pass Motorsports Park is closing, which means the only drag strip left will be in Tucson.

https://classicoldsmobile.com/forums...-track-163156/

https://www.dragzine.com/news/arizon...hway-overpass/

 

Well that's a kick in the teeth aint it....I didn't realize that. Oh well, I can't say I mind a road trip with a few cases of cold beer in the trailer.

 

I would contact Robert master machinist routinely did work for Rick Waters (623 582-1859) he and I have worked together for 30 years, he's in Phoenix 27 ave and Union Hills, my trans builder is also in Prescott, both these people are hard core drag racers and have raced at a high level, and best of all they will not cut corners on your work and are very reasonable. Robert will easily understand what your trying to do.

 

Your cheapest option, low quality.

 

Vortecpro,

I will give Robert a call today after work. Thanks for the number and reference. I'm hoping he might also know where I could pick up a decent trans. Coincidentally, I'm at 51st avenue and Bell Rd in Phoenix so literally 2 miles from Robert.
What a stroke of luck!

Thank you, Mike

 

I lived on Morrow 43rd ave and Union Hills myself. I use Mark Yuccavonne on my trans, he's in Prescott, I will get a number for you.

 

Thanks so much! Its amazing. I don't know anyone, go online and find experts who literally live right around the corner from me.
Unbelievable! You guys are awesome!

 

The mounts are from DMR. They need to be modified to drop the engine 1/2 inch.
1. Drill new holes 1/2" lower than original that secure the mount to the block.
2. Relive areas that interfere with the mount from sitting flush to the threaded bosses. This includes block drains and core plug bosses.

If you find a good transmission builder I would stick with the TH350., It's lighter and takes less power to turn. Plus you won't have to adapt your Dual Gate.

 

That is great advice on the TH350. VortecPro said he would give me contact information for his trans builder here in Arizona. It would be really nice to leave the factory shifter, its sort of the identity of the car.
I would like to keep the TH350 also because its less unused parts I will have to deal with later.

This motor will be 10.75: 1 and I just talked to the machine shop today (Kelley's Machine, Phoenix) and discussed putting screw in studs in the C heads. I was thinking to go with the Torker 455 manifold a Mondello MPV2-3 mechanical cam it has a 2500-6500 power band.

Does anyone have any thoughts on the right cam for a 10.75:1 425 in a 3400lb G-body, 3000stall with 3.90 gears? Am I thinking correctly here or am I missing the boat entirely?

 

VortecPro,

I called Robert at the number you gave. I left a message. I most likely sounded strange because I don't have your name, just your handle on this sight. I hope he doesn't think I'm a psycho. Haha!

 

At 10.75 with iron heads used in a WOT application your going to need to think about fuel. The MVP 1-2 would work good with the 425 CI and that compression. Other can chime in about the vendor. You need to find someone to do the heads if you want to see 11.0. as far as converter wait untill your done with the motor.

 

i just had the best conversation with 66. A fine gentleman. At my age you relish good conversation.
I am not understanding your reference to the dealer for the camshaft Duh.
I hope I am not falling into a bad situation. I will head that warning and stay clear of Mondello.

 

Question?

I have been turned onto Johnson lifters for this build, but when visiting their website I only see roller lifters, both mechanical and hydraulic.
Are there other options for high quality lifters (.921) for the 425?

 

Thank you sir. I so enjoyed our conversation.

 

Concerning Mondelo, I have not bought anything from them since Joe sold the business. I never had any issues. I do however see alot of negative comments from others.

 

Do a google search for (engine parts center .921 lifters) that place has the lifters you need in stock.

 

I contacted Johnson Hylift and found the .921 lifters. Much appreciative. Trying to find a strong cam (235/241, 108cl) if can find it in Hydraulic. Hate to pay Mond…. prices.

 

Believe it or not you can get it made and it's not that much more than off the shelf. Just about any cam manufacture can do it as long as they have a core in stock.

 

Does Tony Silva still work at Kelley's? He used to be a drinking and darts partner of mine. Tell him Dailey says Hi if he's still there.

 

I'm not sure if he is or not, but I will definitely ask and pass along the message.

 

I have a 425 going back together for my '67 Toronado and wonder about the need/ wisdom of oil gallery restrictors. The ones I mean are in the block between the mains and cam bearings. I tore the engine down and the bearings all looked good, at 100k miles, I'm building this for street use,so are these a good idea or not. Anyone with direct personal experience?

 

If you are using a stock replacement oil pump, and have no plans for extended hi-rpm use, you don't need any restrictors. Current wisdom, if you needed restrictors, is not to use the oil gallery restrictors. Instead people use restricted pushrods.

 

I had picked up the melling oil pump listed as high volume, didn't find a stock style direct replacement for the Toronado as the pan/ pickup and windage tray are unique. The Toro pan also carries an additional quart over the normal pan. I still think the strange restrictors are a no go.

 

With the .921 lifters get a cam ground to take advantage of that big lifter

look at mopar .904 lobes ….comp and bullet have no problem doing these lobes on an olds core

 

Unfortunately cores are still scarce.

 

If you have no plans of sustained high rpm driving. Like an hour drive on the highway at close to 4k rpm, I doubt you would need restrictors. But if you'd feel safer you could get restricted pushrods. You just need to remove the valve covers and rockers to get to them.