71 340 Compression Test

nm9stheham said

Just remember that you change the damper and flexplate/flywheel and or TC if you go from a cast 340 crank to a forged 340 crank. The cast crank has balance weights on the damper and flexplate or TC (or flywheel), and is known as externally balanced crank (which is in reality is actually just partially externally balanced).

I see such cranks advertised on places like CL. Caveat emptor....

As for running the higher SCR on iron, that may be fine depending on the cam. Drag eneinges run 11-12-13 all the time but with big cams. The key is your DCR. What do you use this car/engine for? Will you be changing the cam?

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I will mostly drive it around to car shows or maybe a Saturday night cruise. We have a club down here that do 1-2 Saturday night classic cruises each month. Have some friends running those pesky Camero's and making fun of the little 340.
If push comes to shove I would like to shut them up. One has a 383 striker in it. Said it made about 500 hp on paper but no actual Dino tests.
Some things look god on paper but just don't hold up in the real world. I am going to change out th cam and go with something like a 280H/.480"-.480". I think that is about two steps up from the factory cam at about 268H?

Thanks for the info on the forged crank and balancing. What is the damper that you are referring to? Is it the weight on the front of the crankshaft?