[grandprix601]

I have a 81 grand prix with a 231 v6 engine and I was thinking about changing the motor to a v8. I finally found a motor in a monte carlo I think the motor is a 305.. What all do I need from the monte carlo so I can drop the motor in my 81 grand prix?

 

[DoubleVision]

Motor mounts, cross member, fan shroud, radiator, some fuel line routing from drivers to passengers side for fuel pump, exhaust, some minor wire rerouting, and you`ll need the front coil springs, the V8 will make the front end drop by about a inch or more and will effect handling, for your safety swap the coil springs. Other than this, it`s pretty much a direct forward slam dunk swap, did many like it into Olds Cutlasses. If you plan to have A/C you`ll need the monte`s system as well.

 

[357ford]

Are you set on getting the 305?


It would be a good idea to hold out for a 350. They aren't hard to find and they are cheap, best part you'll have a better base to build off of. It may be tempting to jump in and get the 305 have that v8 sound, but don't give up there are 350's everywhere.

 

[Lonestar]

I agree with 357ford, why do all the work for a pathetic little 305. Find a 350 at least. It's just not worth it otherwise.

 

[grandprix601]

Im not planning on racing the car I just want a v8 engine so I can put some flowmasters on it. Thanks for the help.....do u think a shop would charge over 400.00 to swap the motors?

 

[Jzarczyn]

Getting a 305 for the sound alone is a waste of money.
It will burn more gas without giving you the power of a 350, although it will give you the weight to lug around.
That's like buying aftermarket parts just to put thier stickers on a car.

 

[grandprix601]

But I feel like im getting a deal the motor and transmission for 350.00 well actually the whole car.

 

[dadsgp]

transmission

May want to keep the pontiac tranny if it is a 200R4 with overdrive. It should have a combo chevy and BOP bolt pattern so both the 305 or 231 would fit.

 

[grandprix601]

I think the trans is a bop 350 i dont think it will fit chevy

 

[87442lover]

It's a bit more than some people think. Exhaust system has got to go, different suspension, sway bar, (as said) springs, mounts, wiring. Am I missing anything.

The biggest hangup is the suspension system. Just look under the back of any V6 cutlass and than look at the back of any V8 cutlass, you should start to see the differences. Also different rear ends in some. A V6 model will more than likly have the 7.5" when some V8's got the 7.625's and 8.5" rear ends and all performance cars got the 7.625", and 8.5" rear ends.

It is much cheaper to find another 81 pontiac with the V8 setup already there.

Just my 2 cents on the swap.

Do what I'm doing on this V6 cutlass I have, swapping the exhaust from a dead cutlass V8 I have sitting, installing a cam, 4bbl intake, trans, and gearing. It might only get to the 17's or 18's if I'm lucky, but so would a stock 305 pontiac or cutlass. Plus I'm getting all this done for almost nothing.

There's a different view of it for ya.

 

[grandprix601]

And one more thing how will I hook the speedometer back up......would I just run a line straight from the speedometer to the side of the transmission where the speedogear is?