1970 Cutlass Conv.

[Det313]

Hello everyone . I am new to this site and I just love projects. Well where do I start I just towed back a 70 Cutlass from Ohio the car was given to me.!! I have a ? about my motor I don't think it is the original . I found a the original B.O.S from the dealer and it says It came with a 350 rocket. Now from your site and year 1 I have found this much out. Casting # above the water pump 396021 455 Right? with J heads. With a points dist. I don't have much knowlegde about points So should I yank that out too ? Now I want to yank this motor and rebuild it . Any good carb and intake suggestion I would really appr. O I forgot the vin is 342670M199436 .And how can can I tell if I have a Olds motor ???just by the casting # or what !!!!

[texasred]

Welcome, Det.

Your VIN indicates it is a 1970 Cutlass Supreme convertible built in Lansing, Michigan.

That number block was used from 1968 through 1976. Is the "F" plain or is it serif (a little "foot" on the bottom)? Are you sure it's not an "Fa"?

Those are "smog" heads used 1973 through 1976. The chambers are 80 or 82 cc and the exhaust pockets are restrictive. But if you find somebody that REALLY knows what they are doing, they can be dramatically improved.

C.J.

[Det313]

As far as I can tell just plain F

[texasred]

Then it is a 68-70 block with late model heads.

C.J.

[Oldsguy]

What Texasred said........I would comment that a nice aftermarket manifold for that big block would be an Edelbrock O4b if you can find one, they are available on Ebay often. I have one on my 455 in my Delta and it is a good street manifold, develops good vacumm and is better than a stock iron manifold. I am not going to make any recommendations on carburetors because everyone has their favorite but a 4150 800 cfm Holley, an EDL-1413 EPS800 Edelbrock, a Road Demon by Barry Grant or the venerable Qaudrajet by Rochester. Juse make sure you get a manifold that matches the carb or vice versa, square bore to square bore or spread bore to spread bore. Good luck!
BTW a quick way to identify a 350 or 455 is to look for the oil fill tube in the front to the left of the timing chain cover. Also the water bypass in the thermostat housing from the front of the thermostat to the top of the water pump (small diameter hose or pipe) shaped like an upside down J about six inches long. Finally looking for the letter in big blocks or number in small blocks on the left lower side of each head, drivers side would be front under the alternator facing the inner fender low, passenger side hard to see especially with A/C cars but near the tranny dipstick near the firewall facing the inner fender low.

[Det313]

With that O4b intake what type of Distributor can be used ??

[Chumley]

If you have a '70 455 motor, you have better than the original 350 in my opinion! I had a '70 SX that I regrettably sold some 30 years ago, and the car hauled with that engine. I had an Offenhauser intake with a Holley 750,with a Turbo 400 with B&M shift kit behind it all. Ah, the memories.....hang on to that 455!

Chumley

[Oldsguy]

Sorry for the delay on the reply, I miss them sometimes. You will not havve much trouble with a stock points distributor, I had to shave a little bit of plastic material framing the window for adjusting the dwell to make if fit well and enable me to turn the distributor enough but that really isn't an issue. You will not be able to put a newer type distributor in your car as it is just too big. If you want electronic ignition go with an aftermarket conversion kit like Pertronix makes as it all fits inside the old points type distributor. Another option is a Mallory dual or single point distributor, their body is a little slimmer and the distributor sets up about 3/4 inch higher so there is more clearance. Just some thoughts.

[texasred]

Dan,

What do you mean by the HEI being "too big"? Can't you just notch the air cleaner or get a later model one for clearance?

C.J.

[Det313]

Originally Posted by texasred

Dan,

What do you mean by the HEI being "too big"? Can't you just notch the air cleaner or get a later model one for clearance?

C.J.

Yeah wassup with about the Hei being to big

[Oldsguy]

The circumference of the distributor is larger than the old style points distributor and will bump up against the #7 cylinder runner of the intake manifold because it is a dual plane. The manifold is as low as a stock with the same basic design except the runner configuration. On the O4b that runner (#7) makes enough of a dogleg back toward the firewall that it interferes with the distributor. Remember the O4b was designed before HEI distributors were in use. I have one and can confirm this. I plan on using a Mallory distributor because it is going into my '48 and I want to stay old style. If it was going to be in a modern muscle car I would go with HEI or an upgrade kit. My 461 doesn't rev past 4500 rpm anyway so I am not so much concerned with point float, although I do realize that spark is hotter with the HEI or conversion kits. Staying old style has a price that must be paid.

[Brutus_5150]

Why are people talking about F heads when the original thread said he had J heads?