Hey all, been a while since I posted. I'm finally getting back to my 292 project. It's going to the machine shop to be rechecked as after my reassembly of the bottom end, there is significant resistance when turning over the crank, even fully lubed(assembly lube on crank/cam and oil in cylinders). The crank I'm using came with the '67 block and is a six throw 63 only forged crank. Am I going to notice any appreciable difference in terms of engine vibration/driveability over using a 12 throw crank? Also, will a 1970 250" 12 throw crank work if there is a problem with this crank, or is it a different stroke? The motor is going into a 64 GMC 1/2 ton, 700R4 auto, 3.73 gears. The motor is .030" over, propane pistons, stock rods, 3/4 race Crane cam(don't know specs off the top of my head), heated Clifford, 500 CFM Edelbrock, lump port head with 1.60/1.84 valves, Hooker long tube headers. Mainly going to be a daily driver, as I have no racer boy aspirations. Thanks, Ted.

The 250 crank is a shorter stroke than a 292. Jay6155

How about harmonics or vibration from the 6 throw crank then?

I think the 6 counterweight crank does have more harmonics and is the reason GM went to the 12 weight design.
At around 2000 rpm it seems like they have a shake, maybe a slightly higher rpm. and then it goes away.

My preference is the 12 weight. Even though the earliest ones are forged steel with 6 weights.

I also prefer the 12 counter weights. Long as you keep it under 6k rpm you'll be fine. lol