Hey everyone,

Yet another cam question--sorry! I just dragged home a healthy, stock '70 454/390 (from a Caprice). I'll be going through the gaskets so I figured I would swap the cam for something a little more modern. I really don't want to do anything else to the motor; it's a sweetheart. Looking for something that will make it run ok on pump gas. Thanks!

Tony, that's a 10.25:1 motor and you need to run on 91 octane, yes?

Should be 10 to 1. I took apart a low mileage original 70 454 out of an impala and was surprised to find dome cast pistons. THey had about a .100 dome which would make about 10 to 1 with the #290 closed chamber heads

Tony, if you don't mind it deceptively smooth idling, The UD/Lunati 302A7 280/88, should give you a DCR right in the 91 octane range. Cam needs a mild stall is all. As C. Corwel's is showing, will run 12's turning a 2.73 cog.

Originally posted by 427L88:
Tony, if you don't mind it deceptively smooth idling, The UD/Lunati 302A7 280/88, should give you a DCR right in the 91 octane range. Cam needs a mild stall is all. As C. Corwel's is showing, will run 12's turning a 2.73 cog. graemlins/thumbsup.gif


It works very well..even with lazy gear,and idles pretty smooth with lots of vacuum

If you are going to change the gaskets, I would pull the heads off and double check the piston/deck ht. as well as the piston dome size and put it back together with either the correct .022 steel shim or the FelPro .041 gaskets that will drop the compression down. Either way, I would bet your actual comp ratio is less than the factory advertised 10.25/1. A lot will depend on where the piston sits in the hole at TDC.

That Lunati grind sounds great. It would be nice to be able to run a taller gear.