I have a 68 GTO with the same power gear box as a chevelle.What cars will interchange and bolt up the same to improve over the original.I read somewhere that the later monte ss are the same maybe a Z-28 or Trans Am. has anyone done this.I have a 70 Chevelle SS 396 and i was told that it is a little better.

Try this link www.chevelles.com/techref/ftecref29.html (http://www.chevelles.com/techref/ftecref29.html)
phocksphyre recommended it to me in a previous post. It may answer all your questions.
Ed

I'll agree with the tech reference...

Jim L82 did a great job of compiling that data...

As you will see, the later Monte and Z28s are not the ideal choices due to reduced turning radius...

The Caprice Policecars (etc) with the 9C1 option are a pretty good swap, and probably more plentiful than the Monte stuff anyway...

I did the swap to a 1992 Caprice 9C1 box using Lee Manufacturing's hose seat adaptors and Jim's interchange information. I did the swap for under $50 and that includes the box. It's an easy swap that makes the car a lot more enjoyable to drive especially if you have upgraded the suspension to allow you to take corners a little easier.

Did the caprice box bolt up to frame in the same location and did the steering shaft bolt up ok also? My suspension parts are all new ,with poly bushings and hotckis lowering springs.I was going run 17 inch wheels,so i mine as well upgrade the gear box if i can.Is the 92 caprice the only year ? what other cars had this box also.Thanks.

I have an 88 Caprice 9c1 I want to use the box out of for my 69. Is it a straight swap or are the a lot of modifications?

Silk Hope,
That 1988 Caprice 9C1 gear should be a 12.7:1 fast ratio gear. It should bolt right in. You will need a new flex coupling and the aluminum adapters from Tom Lee.

Brian L34,
Not all Caprice gears are 12.7:1 fast ratio gears. From 1988 through 1996 Caprice vehicles with FE, F41, FE2, or Police Packages with FE3 most likely had the fast ratio gears.

Another way to prove that you have a fast ratio gear is to find a two letter ink stamp or a paper tag with two letters on the aluminum end plug and/or the aluminum side (top) cover. If the two letter code matches any of the following, you have a fast ratio gear: WZ, CP, FB, HL, CT, DU, TW, MX, or KW.

Lastly, if you know that your gear came from a 1988 through 1996 Caprice and it has just 3 turns full lock to full lock, you most likely have a fast ratio gear.

Finally, if you can find a late 1992 through 1998 Jeep Grand Cherokee power gear it will be a fast ratio gear just like the Caprice gears and it will bolt right into your 1968 GTO.

JIML82