After my gear swap I found out I have a the wrong driveshaft in my car.
I have the driveshaft for an 8 3/4 rear wich is 52" I need a 51" per the manual, actually 50.96" anyway instead of shortening a good 8 3/4 rear driveshaft That I can save for another car I thought I can use what I had handy.
I have an aluminum driveshaft from a crown vic police car. it has 1330 u joints. I was quoted $75.00 to shorten and balance it. Then I would use a 1330/7290 conversion joint.
I think this should work fine
Is this a bad idea ? if so please explain.
I kinda dont want to buy a custom shaft or change the trans and rear end yoke if I dont have to.

I don't see why that would be a bad thing.
use the Brute Force or extreme duty u joints with no grease fittings. link to the u joints

The "cross" for the Spicer u-joints that I have are the same for the 1330 and 7290, only the caps are different. If your's is the same, then you'll only need to change the caps.

Is that the part number for the 1330/7290 joint? if not anybody have the part number?

Spicer # 5-796X is the 1330/7290 U-joint

Whats the diameter on the alum shaft and how much
power are you making

just under 3 1/2" diameter and I am making about 550hp. Is that going to be o.k. in a heavy car or should I stick to steel?

for the most part yes it is,
I have plans to run it this summer now that the kiddo is a little older.
we have 1/8 mile pretty close and I am going to start there. If I can get to the track 4-6 times a year I would be happy.

I have a crown vic drive shaft in my Valiant. I think your going to be OK
The Valiant has been 1.31 in sixty feet with a 500ci wedge