engine swap

[bonesninja 5,000+ posts]

ok so i bought a 76 grand prix off of one of my dudes. the car itself is a wreck but it has a good motor and tranny which is what i was after..its a pontiac 6.6liter 400 with a 400 tranny. i have my 81 cutty with a V6. i want to drop that 400 in my car and my question is do you think i will have to get a custom length driveshaft for this? Also do you believe that i will need to use his rear end or will i just need to gear my stock rear?

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[RandyJ 10+ year member]

If you are going to go with new gears, in a v6 motor, why not just get something better, like a Ford 9" or Old GM 12bolt //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif OR, the rearend from the pontiac //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I think this is what I would do, but it depends on what you're looking for..

And the custom driveshaft will all depend on lengths as you already know. Do some measuring and see how long the combo is from motor mount to the yoke, and then measure from the predicted yoke placement to the pinion. Then search online for that given shaft length. There are ways of making it fit though, I suggest some searching at http://www.clubhotrod.com

 

[bonesninja 5,000+ posts]

well his rearend is wider than mine is so its not just a direct replacement. And i think my rear housing is the same one used in the bigger V8's its just geared differently.

 

[RandyJ 10+ year member]

well his rearend is wider than mine is so its not just a direct replacement. And i think my rear housing is the same one used in the bigger V8's its just geared differently.

Well, if you can confirm that it will hold the power (Assuming the motor is running properly), then go ahead and keep what ya got. You may not even need new gears, what do you have in it now?

 

[bonesninja 5,000+ posts]

oh its geared for cruising not any kind of power or low end ... its like 2:85 to 1 or something crazy like that.

 

[RandyJ 10+ year member]

What do you want?

 

[bonesninja 5,000+ posts]

like 4:10 gears or close

 

[RandyJ 10+ year member]

I meant from the car. Will it be a strip car?

 

[regal8r 5,000+ posts]

best bet would be to join an oldsmobile forum and ask them...

 

[RandyJ 10+ year member]

best bet would be to join an oldsmobile forum and ask them...

I'm not sure an olds forum would have enough exposure to obtain the members needed to answer this complete question for him. Some forum like chr would be able to though, hence why I directed him to it.

 

[bonesninja 5,000+ posts]

yeah i tried the olds forums but with only 8-9 members no one will answer. this will be street only but i want the ability to get a little nuts and roast tires and shyt occasionally. mainly i just want it to be sound great with headers and duals and be able to toast all the little neons and ricers around here. i can already do that in my mustang but i just hate going from my 5.0 to my SLOW cutty.