Rear end swap question

[86 Grand prix]

I have read every thread on here on rear end swaps but am still confused. I am building a vortec to go in my GP and am expecting around 375 HP. I plan to drive the car and will punch it at times but never plan to race. I currently have an open 7.5" with 2something gears. Now I know an 8.5" out of a G body will bolt in but none to be found. I read that I can put and 8.8" out of a Mustang in with an upper arm kit but they all seem to be four lug. I found a Thunderbird turbocoupe at the local yard but it is four lug also. So here is the question. Is there a Mustang or thunderbird or other ford with the five lug 8.8 and with upper arm brackets and the correct length? Or with my set up and street tires am I OK getting a posi carrier out of an S10 and changing gears in my housing?

 

[565bbchevy]

If you are looking for a complete bolt in rear end then I would stick with a gbody 8.5 or an aftermarket 9" but for 375 horse I would save your money and build up the 7.5 with a decent carrier and gears and maybe upgrade the axles and it will be more than adequate for your power level and you can also get a rear end support cover and brace kit for added power.
I had my 7.5 with an Auburn carrier and Richmond 373 gears everything else stock behind a 496 Big Block Chevy and never broke the rear end because it never hooked but on a track with slicks might have been a different story.
You can always sell your newly built 7.5 down the road if you decide to step up the power and do a serious rearend upgrade.

 

[cutty454bbc]

I agree with the 7.5 for your application. I have a 454 pushing about 400 estimated horse and the 7.5 stood up to full blown bracket racing. I had Moser axles with C-clip eliminators, 4.10 gears, supported diff cover, Mini spool, welded axle tubes and no hop bars. It ran mid 12s @1350 ft above sea level and the only thing I ever hurt was slight damage on the mini- spool itself because it hooked really hard with the slicks.

 

[86 Grand prix]

Well thats two for a beefed up 7.5. I figured after reading all of the old stuff that the 7.5 would be trash.