Rebuilding a 1970 Cutlass 350 engine to factory specifications. The car has an automatic, 4-bbl carburetor, air conditioning, power brakes, and 3.23 axle ratio. Someone suggested to install a camshaft with specifications for a 1970 automatic 442. Would this require any changes or modifications due to the increased duration?

 

The 1970 W-30 automatic cam is mild. It does not have a lope and produces good vacuum.

If you are set on using a factory cam, it has a good balance between performance and smoothness.

Modern cams would give more power with the same smoothness, however. Send a pm to cutlassefi if interested. He'll give you good advice.

 

You have decent gearing, definitely helps. I went with a custom Erson from Cutlassefi, slightly less duration, 214/214 vs the 216/217 of that cam and a 110 LSA vs I believe a 113 LSA. Both had .472 lift. The 455 cam was the 70 350 manual trans cam which ran mid 15's with your same 3.23 gearing back then. My Erson cam worked great with a 2350 flash stall and 2.78 gears. It idled near stock with good manners and decent mileage. The 2004R trans died, so the stock TH350 trans and the factory 1600 stall went back in. It went from 1/4 block burnouts to not peeling skin off a grape. More cam needs more stall. Consider the 10cc dish Mahle over the ancient Speedpro flat tops. They will give mid 9 to 1 compression with early heads. Unless you 0 deck the block, the Speedpro flat tops will barely produce higher compression, .025" below deck, the Mahle are half that. Plus the Mahle only need .0025" piston to wall, again half of the Speedpro pistons. While out, swap the factory converter. Guys have had good luck with the affordable Jegs 2000 to 2300 stall which is supposedly a B&M converter. Good luck👍

 

No changes really required. Might like a slight increase in torque converter.

 

Cam technology and lobe profiles have come a long way since 1970. Contact Mark Remmel and get a cam for your specific application. He's really good at matching profile to the car and intended use.

 

Lunatipower.com. has a lot of short duration profiles listed.

 

Thanks to everyone for their input. Decided to use the 1970 442 automatic cam. Will be ordering from Supercars Unlimited. Will also retain rotators on the intake and exhaust valves.

Is it correct all ‘70 & ‘72 350 and 455 engines used rotators on the intake and exhaust valves?

And other than the W30, which reportedly used rotators on intake and exhaust valves, the ‘71 350 and 455 engines used rotators only on the exhaust valves?

 

Do you know what your compression is? Compression plays a big part in economy.

 

The factory 10.5 compression.