i just bought a 76 350 2 piece rear main seal longblock without a flywheel...what flywheel do i need for a 700r4 transmission ? i have this odd shaped plate at rear of engine where the flywheel bolts to.how can you tell if you have a internalor externlly balance engine? thanks

 

the 1 piece seal flex plates are doweled and have a differant bolt circle so they don't interchange. you'd need one that bolted up, and didn't have a weight atteched. easiest way to tell id the dampner, simetrical is internal. use to be you could look at fly wheel/flex plates for weight but with the 1 piece rear seals gm added the bat wing weight to off set the mass removed from the flywheel flange on the crank, but it's still an internal ballanced engine. you can also look at the counter weights on the crank and if the radius is smooth it's internal and if the weight has been machined or made flat where it's contact the piston it's external

 

thanks for the help