v6 to v8 swap

i know the cooling system will need an upgrade, the engine cradle has a extra set of holes for motor mounts , but will the rear end handel 400 hp?any other info will be helpfull

you have what is called an open differential which only drives one wheel all the time no matter what. Technically it will be fine as long as you dont put slicks on it. But if you dont get a posi rear end and some decent tires there wont even be a point in having 400 hp because you will be all over the road.

what year is it? i have been told that the rear end can handle it but i don't know for sure

You'll also need to upgrade your front springs to handle the extra weight (Unless its an Ls1, that thing is lighter than my v6!) also a new transmission to fit the v8.

Just saying incase you didnt know already :)

changing a rear isnt a big deal at all. Couple of guys of here have done in their driveways. A posi or limited slip 10 bolt out of z28(82-02) will give you added traction and is a little stronger. Still cant put slicks on them but some drag radials would work but dont expect it to last forever. Any rear end will take any amount of power as long as you dont have traction.

You'll lose serious benefits of the engine swap if you leave the 6'r rear end in (which won't live a long happy life anyway). Plus unless you had a 3.8 V6 in it, you'll need a new trans.

Plus unless you had a 3.8 V6 in it, you'll need a new trans.
really? a 3.8 tranny will work with a v8 swap? didn't know that...

really dont think it will....

i didn't either....

Yes it will, a 3.8 is 90 degree motor. All of the lessors 3.4, 3.1, 2.8 are 60 degree motors and thus require a narrower bellhousing bolt pattern.

ok so it will bolt up....But I would think that it would blow up before taking much power.

Well, i had ass-u-me'd that they'd know a 8 makes a heck of alot more tq then 6 and the internals would need some attention.

I think everything on a v6 trans and a v8 are the same except the bellhouse

eh....400hp and 400+ torque would blow up both the stock 8 and 6 trans....point is if you need to you can use the trans but dont waste your time.

is this guy even still around or are we just talking to ourselves?

that's neat to know...i didn't know that....coolness

That's why if you look, you'll see alot more 3.8's going into retro modern projects, decent power and mileage.

But there is a difference in rwd vs fwd applications.

well, i still say thats neat...didn't know that.

this is a 2.8l its a 87 model and its has limited slip dif i knew the trans would have to be junked along with the torque converter im mostly worried about drive shaft length and if i would have to relocate the trans crossmember, as for rear end changeout im not worried about that ive changed out plenty, ive built a few cars all witch were factory v8's ive never done the 6 to 8 swap

the driveshaft should be okay, they were interchangable from 82-02 i believe, formulalt1 has some for sale

or had at least.....

thanks for the info ill keep you all posted when i start the prodject im currently driving the car believe it or not it only has 84,000 miles on it
my uncle gave me the car he had it sitting in the garage for the last
7 years only driving it 3 or 4 times a year recently i lost a lifter in it and i dont feel like messing around with fixing it right now any way if im gonna fix it im going to fix it right with a 350 , witch i have sitting in pieces 350 4 bolt bored 40 over, 400 sb double hump heads 10.2:1 cast alm pistons, a custom turned cam i got from a friends uncle witch should be sweet since he used to race road track for maseratti, solid lifters adj titanium pushrods, and alm roller rockers,thinking on getting a pete jackson gear timing kit, and i have some large valves sitting around im going to stuff into the heads ill post pics of assembly in a few months when i get started on the engine.

WHOA WHOA WHOA


a 3.8 tranny will NOT bolt up to a v8!

different bolt patterns.

Just figured I would clear this up...

didnt think so...

yea, and I believe the input shafts may be different lengths as well.

Another thing to clear up is in terms of the RWD 3.8's, the 4l60e is internally the same as the LT1/LS1 4l60e

3.8 tranny definatly not going to bolt up to a v8, more than likely im going to use a turbo 350 or a powerglide, the only way a v6 tranny is going to bolt up is if you make a bellhousing adapter

that's what i thought...small block and big block bolt patterns are the same, but they are v8 specific

Kasey I wouldn't doubt you for a second when it comes down to as you stated, a current 3.8L to 4L60 (700).

I was thinking of the 3.8s of the mid 70's to late 80's in the Montes, Cutlatss and Regal, to maybe a 300 or th350.

Maybe i just didn't notice, but the few roadsters i 've seen with a 3.8L in 'em didn't have and adapters.

wow what i thought was a bad lifter turned out to be something al bit more than that, i was riding down the road and the ticking stoped i was thinking the lifter had finaly pumped up cool i thought then a loud grinding sound, kinda like something was wrapped around the drive shaft , i through the car up on stands could not find anything loose i got to looking at the torque converter inspection cover and there was a freahs hole in it i pulledit off and behold 2 large chunks of metal fell out everything is dry in there all the torque converter mounts and bolts inplace must have had been part of the flywheel had broken i cant tell could not see anything wrong ohh well ill drive it till it dyes then put the 350 in it