[steve25]

I assume that since you are running dome pistions that your E heads are not the 72 cc version?

With that Crower Cam and your CID you not going to need to shift above 6000 rpm, so I would shim the pump for 70 psi and call it good.

All 455 cranks are crossdrilled from the factory so they oil the Rods some 30% more then the 3.00" main journal cranks as it is even without the use of half groove Bearings.
The added pressure is needed strictly for the 4.210" mains.

Any unneeded pressure and rod side clearance will only serve to put more oil draped around the rotating crank & Rods and this leads to a power loss and potential oil control issues

[wh33lman]

Originally Posted by steve25

I assume that since you are running dome pistions that your E heads are not the 72 cc version?

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.

[chiefbigb]

I would run a 80 psi pump. Have built many with similar clearance. I use vr1 20 50 also.

[blueghoast]

Originally Posted by chiefbigb

I would run a 80 psi pump. Have built many with similar clearance. I use vr1 20 50 also.

X2 here

GT

[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.