IDK what a 508 cam is.
But,
If you really have a true 10.5Scr,
and your Ica is say 66*,
and yur at 1000ft elevation or less,
Then your CCP is likely to already be at the max for iron heads and best pumpgas.
If yur at 5000ft, well, yur gunna have to re-engineer your combo.
If your convertor is stock;
Let's say your engine makes 340 ftlbs at a stall of 2000rpm; that is 129hp.
Lets say you increase the stall-Timing right up to the point of detonation, less 2degrees. How much power can you expect to gain?
I'll tell you; not much.
Let's say you
swap in a 3000, to better match that cam. Suppose your torque/power jumps from 340@2000/129hp, to
380@3000/217hp. That's a pretty substantial increase.
If you already have a higher stall, then my guess is that your cam-timing is off, or your skirts/ring-gaps are too tight..
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My engine is similar to yours, but with a 230*/110cam, and a 4speed with 3.55s.
In First at WOT, it is impossible to not spin the 295/50 BFGs. She will burn right thru First. In fact, I can hit the Line-loc atta stop, bust the tires loose, and idle the engine down to say 1200; then just let her idle there with the tires singing a mournful song.
In Second, she will initiate spin at up to 50 mph.
If the tires are spinning at 50, then they often continue spinning into Third gear.
Now
I know T/As are traction-deficient, so I bought a pair of 325/50-15 D/Rs, with no change. Not cold and not hot either.
But the 295's are way more fun around town.
Happy HotRodding