Another Dumb Ford Question

[pspeaks]

Yes, another dumb question about a Ford motor from a Chevy guy.  I'm building a 78' 302 which is a 28.2 oz motor and have been told I can use a 50 oz flywheel if I also switch to a 50 oz harmonic balancer.  Assuming, because I have no idea how to tell by looking, that I actually have a 28.2, can I actually put a 50 oz balancer on a 78 crank.  I've asked before but no one responded, how can you tell.

[rficalora]

Paul, it's been too long since i researched that to remember for sure, but I believe the crank, balancer, & flywheel all have to be 28oz or 50oz, not mix & match.  So if you switch to 50oz flywheel/balancer, you need the crank to go with that rotating assy.

Unless you know the history, I'd cross reference the crank number to be sure.  It could have been swapped out at some earlier point in the motor's life.

[mgv8vt]

A 28 oz crank can only be used with 28 oz flywheel/damper. The counterweights are much larger on the earlier cranks, requiring less external balance. An externally balanced engine uses the added weight of the flywheel/damper to attain the required bobweight total. I've reduced many 50 oz balancers and flywheels by milling/drilling to use on a 28 oz crank. A lot of Mustang guys doing stroker kits in later cars of course have the heavier external parts. Most of the 4340 stroker cranks can be balanced with 28 oz externals and that's why I do it this way. Otherwise you'd have to take a ton of meat out of the crank. Ask your local machine shop if they can do this with their balancer. Not all balancing machines can measure the imbalance this way. Whoever told you that you can simply use the heavier damper/flywheel has never actually done it, trust me! It' would shake so badly you'd think that half the plug wires were off. Hope this makes it clear as mud..

[pspeaks]

Thanks guys, I'm giong to take your advise and stick with a 28.2 ounce flywheel.  I've tried to find one that doesn't cost $300.00 but it looks like I'll have to bite the bullet.  For over 20 years the GT was my daily driver and as I would like to return it to active duty I'm trying to keep the motor as stock as possible for fuel economy and driveability.  As I live in the Dallas area, and deal with intense traffic, most of my friends think I'm crazy for not putting an automatic in it but so far I've resisted.