Hey guys, I took my 89 cc olds and put in a rocket 350 with flat top pistons and a mild cam, Msd atomic fuel system. Ive rebuilt the trans with a valve box and governor from a grand national. My question is what rear end is in the wagon factory and what should i upgrade it to? Id still like to cruise 70mph but have a good launch off the line.

 

My 89 Custom Cruiser had a 403. Given the fairly large tires, I used a 3.90 rear. With the 4 speed overdrive, this was perfect.

My 88 Cutlass RWD, also a 403, has smaller tires and there I used a 3.73.

 

In a heavy wagon either the 3.73 or 3.90 is a good choice depending on tire size. I find this calculator very accurate with the lock up torque converter engaged. http://tech.oldsgmail.com

 

Hope you have an OD trans if you want to cruise at 70 with a 3.73 or 3.90.

 

That car factory has a 2004R and upgraded some parts.

 

Pardon my ignorance...is a CC a Cutlass or Custom Cruiser? I guess I'm asking if it's a B or G Body...

 

The Custom Cruiser is the B/C body which means 8.5" rear ends are an easy to find item.