289 v 302

Hi guys. Can I put a 5.0 crank in a 289 block? I think the bores go a little deeper into the crank case but what about the rear seal? Are they one piece or two?

Thanks

The bores do not go deeper into the crankcase on a 289..The rear seal is a 2 piece design..I think the 5.0 crank can be machined to fit but why go to all the hassle?...Also be aware the 289 crank and the 5.0 crank are balanced differently and the 289 has a different length rod than a 302/5.0...That may be of no concern depending on what you are doing..

Can you do it? Well , it can be done if you have the money, time and desire. If you want a 302 then buy a 302 - they are cheap, you can get a transmission with it that will work, and no one can tell by looking that it isn't a 289.

Thanks guys, I was planing on doing a Boss style motor for my 65, was looking at using bits I had laying around. I have the original 289 that came with the car. As affordable Boss pistons are hard to find, I went looking for other options. I can run a 289 crank, 302 rods with cleveland pistons. This combination has pistons with the valve reliefs in the right place for the cleveland head. Obviously!!! The only difference is the piston to deck height is .020 to .040 to low. (depends on what spec sheet you read!) Easy enough to deck the block .040. So we finish with a 289 Boss. What do you think??

The 289 rods are the same length as the boss 302s..Are the boss pistons so expensive they would still cost more without the extra machining to the block?

Boss 302 pistons have a different deck height and will stick out the top of the block - that is why he is using the Cleaveland pistons.
Yes it will be relatively inexpensive to deck the block .030 - .040" and it will assure enough quench for decent detonation resistance.

My theory is that you deck the block when you do a rebuild so why not take a few extra thou and use an off the shelf piston. I had one other question.... if I take say .040 off the decks do I need to take the same off the inlet manifold face between the cylinder decks?

And to frdnut, put it this way.... the only Boss pistons I can track down are custom ones made to order. But if you now where I could get Boss pistons at the right price I'd be most grateful.

Thanks