dghost22

I purchased a 68 289 bare block today and I have a question for you all. Is it worth it to build a motor for my GT with it or should i start with a 302 block? I am looking to make approximately 375-400 rwhp with the motor. Any advice would be greatly appreciated.

Thanks in advance

TheGmKiller331

Thats pushing it.

Blocks are identical its the internals that are different.

Also make sure its not the 5 bolt instead of the 6 if so good luck finding a tranny..You will be very limited.

pichinco

Is it a '64 block or a '68 block? '64 is worth a ****load it's a D-code engine and bare block alone is worth >$500 to someone trying to restore a '64.5 car. Trust me I looked for one!!

289 and 302 are same engine, just longer stroke on the 302. Therefore the 289 is a higher revving engine, but 302 has more torque. So depends on what you want. Not sure about the bolt pattern on the '68 versus the newer GT bellhousings. Like GM said, better match up your bolt patterns.

dghost22

The block is definitely a 64 289 block. From what I could find, it was one of the first 6 bolt 289 blocks. I am not sure it is what I should use to build a motor for this car.

Milky

I always thought the 302 was just a 289 stroked a little more but I heard somewhere else it was the bore.. can someone clarify for sure, not just what they think they know?

roundman

I'd keep the block and sell it like someone already said. get a 5.0 roller block so you can put a roller cam in your motor and you'll come out way ahead of what you could do with the old block.

pichinco

No, bore is the same. Just longer stroke.

pichinco

I'm pretty sure the 64 were 5-bolt. First 6-bolts were 65, part of the reason it's such a pain in the butt to restore D-code Mustangs. Arguably the rarest engine option ever for a Mustang. Only made April-September of '64. If it's a 5 bolt it's a 65 of that I'm pretty sure of that. Defintely the older 289's had a narrow transmission bolt pattern compared to later ones.

What's the casting number on the block? I used to be able to track down from that year, and car model the engine came from. Been a while, I may have to strain.

REALLY wishing I still had my 64.5 now. Somebody dropped a 302-2v 3-speed in it. Originally had been 289-4v 4-speed. Had most of the pieces with the exception of the correct block.

dghost22

The casting number is C5ae-6015e the date code is 4H29. It is definitely a 6 bolt block unless I forgot how to count . It is in decent shape. As for the difference in the 289 and the 302, my understanding is the larger crank makes it a 302. I could be wrong but that is what i was told. Here is a picture of the block......

I also need to correct my first post, I meant to say the block was a 64 and not a 68. I have what I believe to be a set of 68 289 heads but I am still working on decoding them. They were on my mind when I wrote the original post, hence the "68" rather than the 64. Sorry for the mixup

pichinco

C5 means it's a 65, the rest I'll have to work on. It's not a 64 block.