I am seeing different advantages to both. Looks like I have found a 351 CJ for my car, but I am conflicted on the transmission. Can a C4 handle a 351CJ, would I be better off with a C6, will I lose too much HP from the C6, is it more important to save weight with the C4 ?????? Help please! I have a long way to go before I am ready for this season.... Thanks, Jeff  

A good built C-4 will hold up in there.  A C-6 takes around 45hp in hi gear to turn and a C-4 takes about 20.  

Subject: PA transmissions 2008
To whom it may concern, PA transmissions are a far cry from a performance tranny. I recently had a bad experience with this company and doubt that I am the only person to have such issues with their product. I purchased a Super Streeter C4 from Mustangs Unlimited. I had the C4 in for about two months (100miles) before third gear let go. I tried all the normal fixes and nothing helped. After a call to PA, I was told to pull the tranny and ship it to them at my cost of course. During this conversation it was also brought to my attention that I would have to pay for return shipping as well. So, for a total of $500 in shipping I could get the tranny rebuilt. It doesn’t take a rocket scientist to figure out that you can get a local rebuild for $350. Not only was it going to be a complete rebuild but I could get blue clutches (much better than Alto Red) all with correct end play which ended up being the issue.

There was so much endplay that the 2-3 shift popped the output shaft lock ring off. This allowed the shaft to move forward and cover the fluid travel holes. There were also a few seals lying in the tranny as well as a broken drum. Did I mention that the so called heavy duty clutches were stock paper clutches? They also used plastic rings instead of steel. I even sent pictures of the failure to PA who at first seemed as though they were concerned that I had problems with the tranny. They hinted at paying me for the labor bill. I have called three times with the same answer. “It’s up to my boss now”. So, I don’t expect them to pay. They burned me and I hope that I can save others from the same trouble. In all I lost $400 not to mention my time to pull and re-install the tranny. DO NOT BUY FROM THIS COMPANY.