88Mustang302

Hey yall. Im a new member here and this is my first post. I got my first mustang. Its a 1988 lx 302, t5. I just got motor back from the machine shop. I had the block bored .030 over, crank turned .010, rods reconditioned and had arp bolts installed. I ordered a set of speed pro forged aluminum pistons that were supposed to be factory replacements (jegs part #8-KL2482F30). But Ive encountered a huge problem. I put the number 1 piston in and when i turn the crankshaft the bottom of the piston is hitting counterweight on the crank. Does anyone have an idea why? Could the pistons be wrong or is their anything else i should look for? I believe everything is stock.

The numbers on the block are: 23 e7te ca s
The numbers on the crank are : e7ae aa 19d
The numbers on the rods are c80e a ano51

woodsy

The skirt or the pin tower is hitting the counterweight? Also was the rotating assembly rebalanced?

Tims 88GT

They are the wrong pistons. You should not have any contact with the piston or the crank.

88Mustang302

Thanks for the replay. The pin tower is hitting the counterweight. Yea I had it rebalanced.

Tims 88GT

Just my 2 cents also. Speed pro pistons are junk. I have seen a lot of problems with them.

88Mustang302

Thats what I was thinking but the pistons are suppose to be a direct replacement. Is there anything else I should check before I send them back? Like what is the stock piston height for a 302?

Tims 88GT

I am not sure what the specs are on a 5.0 anymore. I switched to mod motors a few years ago. I am sure someone else knows the specs.

88Mustang302

What would yall recommend for a stock replacement piston?

Tims 88GT

Honestly if you can get trw's they are good, ross are great but not cheap, je, and trick flow. Any of thoes and you cant go wrong.

woodsy

1.600, but all manufacturers will vary on comp height. Your next problem is piston weight since you already had it balanced, you need to find a piston that is very close in weight.