Go to oldGMCtrucks.com....the search function is your friend.
Also check out Patrick's Antique motor parts, as they seem to be the most complete supplier of Jimmy parts.
Not familiar with a Clifford 2 barrel manifold. What carb is that?
The Fenton headers will require a little grinding work to properly fit a GMC.
The stock head on your '58 should be #2194819. Smaller ports
and chamber than the 302, but same valve size. Some street guys seem to prefer it for high velocity and compression boost.
A cam change should be at the heart(brain) of your plan.
Delta Cam in Washington just reground one for me. $125 including lifter resurface and return postage.
If your short block is solid, money can be saved as performance pistons are a major expense.
But ain't none of it cheap !! Even the machine shop wants a premium for jacking around these huge chunks of iron.
