1972 Demon 340 engine mods
His idea is to add some more power to make it more fun to drive, but all work needs to be done so that he can go back to stock specs whenever he wants to.
We were kind of debating what to do here not to go too crazy.
The most radical idea included swapping heads, cam, intake and carb...
Going back to original means not changing the pistons. so the idea of swapping out the top end parts is the ticket IMHO.
Is this for drag racing or for brisk cruising or what? That will decide the cam and that will guide the top end changes. If 'twer me, and I had the $$, and it was for street, I would be looking into swapping out the heads for Edelbrocks, with an Air Gap or Performer intake and then choose the cam and carb for what I I wanted to do. The breathing of those heads and intakes will get you easily up into or past the mid 300 HP range, even with stock manifolds. Headers would be even better.
I'd have to run the numbers on the resulting compression ratio to be sure, but off the cuff, I would expect the real static CR to be in the low to mid 9's with 63 cc head chambers with those lower CR 340 pistons. So low RPM torque will be pretty darned good, and the torque band can be made wider. That will help with the wider RPM range needed with that 3 speed.
It appears that Edelbrock has removed their restrictions on the dealers and distributors marking down the price on the Edelbrock heads. I see that all sorts of dealers are selling the 60779's for $683 each, fully loaded with valves and springs. That is down $130 apiece form not so long ago.
You'll always be able to easily sell such heads and the intake, etc., later.
Now, he needs to do something about that 3 speed....