I staarted with a leaking intake gasket. When I removed the intake manifold I found a push rod no longer in its lifter. Took the valve cover off and found a broken spring. Explains why the engine ran poorly. I removed the heads and took it to a machine shop. These are the 462624 heads. No surprise to you familiar with these heads when I tell you they were cracked. One repairable and one not. Doesn't matter, no one would stick any money into these heads.

I was planning to remove the engine this winter to detail it, detail the engine compartment and replace the evap coil. So, by circumstance, I have already started. The block is at the machine shop too.

Was not prepared for this but onward. I prefer to keep the L82 block with matching number. The machinist recommends boring the cylinders .030, doing some work to the crank, rods and bearings. He will work up an estimate when I know more about what I want to do.

First decision I need to make is which heads to use. Vortecs are cheaper but then I need to add cost for new vortec manifold and valve covers. The intake valve is 1.96 versus 2.0 with the stock heads. Seems close enough. The vortec flows much better, 170cc vs stock 155. Smaller 65 cc combustion chamber with heart shape. So I conclude the vortec is a big improvement over the 624's. Do you agree?

Or I could use AFR aluminum heads with bigger valves like the stock 624's. Smaller 65cc combustion chamber. Very expensive but better. I think!

Would / could someone run the calculations as to what horsepower and torque the vortex and the AFR 180 cc would generate? I. Don't know all the specs like the distance from the top of the flat top piston to the top of the cylinder bore but I would guess similar to all other L82's.

This car is a street car. No racing, and I dont drive very hard. But I do enjoy a good punch now and then.

Rear end is 3.73 and it is a four speed.

I then need to make a value judgement on the expected results and cost of vortec heads, AFR heads, or a crate.

Thanks for reading and thank for whatever help you can offer.

Jim

 

Built my 77 with a 4 bolt block, heads are World Product/Dart cast iron 2.02/1.60 valves, 64 cc chambers, 200 int runners...would have used smaller runners if I did that over. Alum better I keep hearing but more expense...mine runs well but I did a lot more to the rest. 3.73 rear with 700R4 trans--great drivability and decent fuel all things considered.