[78w72]

Originally Posted by wh33lman

Actually they are a very early version of the Performer RPM that is 87cc.
Between the block decked and heads shaved, the Venolia pistons had to be shaved down to lower compression to 11.5:1.

Motor spent most of its life in a 1975 Firebird Pro Street car (2800lbs., 4:11 gears, tube chassis, big tire, CC290B solid cam). So I had to make some changes to use in my 81 TA street car.

If its in a street car now its safe to assume it wont be raced or spun over 6000-6500 rpm... if thats the case then why would it want or need an 80psi pump... or 20/50 oil?

If the rpms are ~6000 and the car will be used mostly as a street car, stick with the 60psi pump and maybe consider shimming it for a little more psi. If using in spring/fall cooler temps, use an oil weight that provides good hot/cold psi, 10/30 or 10/40 should be perfectly fine.

The best option for this questions would be to ask the builder who built the engine what he suggests for a pump and oil weight, but then weigh that answer just like the others here & use what works best for the intended purpose of the car. Excessive pump psi &/or oil weight has no benefit to an engine that doesnt need it.