I am going to build either a 383 or 396. I plan to use a 1987 or latter roller block but I am not sure what crankshaft design to use, or how to balance it? There are a few companies who make 3.75 and 3.875 stroke one piece seal crankshafts for the 1986 and latter blocks. These crankshafts use the latter design 1986 and up flywheels. My question is how are these engines balanced and what flywheels do you use? The 400 crankshafts from the factory were externally balanced with a special flywheel and harmonic balancer. The latter 1986 and up 350 flywheels are also externally balanced but they were never designed to work with the 400 style engine. What parts do I need to balance this engine? Do I internally balance the 400 crank and use a neutral balanced flywheel and balancer, if so where do I get a neutral balanced 1986 or latter flywheel? Do I use the 1986 and latter balancer and flywheel and have them rebalanced to work with the 400 style crank? Do I use something completely different? I need to keep the smaller 153 tooth flywheel design.

Thanks

 

i don't know about the 153 thooth flywheel. but if you want to use the 400 crank which has 3.75" stroke you can use its flywheel and balancer.

these 4340 3.75" (383) and 3.875" (396) forged steel cranks are usualy internaly balanced using your current balancer and flywheel (i mean you have to send the stroker kit to a shop to balance the stroker kit). if you use cast steel crank such as scat crank they extanaly balance it using your flywheel and maybe your balancer.