Never did find anything really terrible in the engine. 452 heads dad ported, L2355 forged 6-pack pistons, .012" deck height, 9.5:1 compression, 1.6 Crane Gold Race rockers, Smith Brothers pushrods, some kind of 7 degree spring retainers I had never seen before.
I guess the Comp 260H 212/212 @ .050 cam and the stock distributor that had 40 degrees mechanical advance is probably what resulted in the detonatiion. The fact that the retainer to seal clearance was insufficient and the seals were getting destroyed letting the valves suck oil into the combustion chamber didn't help either.
The bottom end was still holding 70 PSI oil pressure so we'll use the short block to build the mule.
I'm guessing we'll start with a Comp XE285HL and the 346 heads with the stock 2.08/1.74 valves. They're flowing,
.100.............88/59
.200...........164/114
.300...........210/158
.400...........236/194
.500...........259/211
.600...........270/224
.700...........280/234
With the 1.6 rockers we'll have .574 lift. There are a lot of intake manifolds laying around here but we'll start with the Edlebrock Performer RPM that Pop had on the engine. I'll have to modify the distributor so that it has no more than 14-15 degrees mechanical advance. That'll work until we drop in the old 1967 Racer Brown 72R Straddle Roller camshaft.
We'll run the 346 heads in different variations until we have the flows in the 300 cfm range to get a direct comparison to flow and horsepower, and then make a switch to our ported Indy EZ heads that are flowing right at 350 cfm @ .600". I've wondered what kind of effect that much flow would have with a small cam like the XE285HL. Trouble is, the small 75cc combustion chamber will result in a static compression that I consider way too much for that small of a cam on pump gas. Maybe use the roller to keep the dynamic down to test the differences. We'll just have to see how it all shakes out.
