Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: Tbird 83 on March 29, 2005, 08:35:21 AM

Title: Tbird 83 v6 3.8L to V8 5.0L
Post by: Tbird 83 on March 29, 2005, 08:35:21 AM
I have been told that the 302 fits on my tranny and the mounting supports should be the same. Now the only thing is that im not sure if it s from a reliable source. So if u guys can help me out and reassure me it would be greatfull.

Another question I have to ask do u guys know if its possible to put a 4 barell carb on a v8 5.0L that currently has a 2 barrel carb?

Thanks in advance!
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: Ifixyawata on March 29, 2005, 02:48:01 PM
The 4-barrel swap will be easy.  You just need another intake manifold, they can be had brand new for $150 or so. 

As far as the transmission compatibility, I'm not sure.  If I'm not mistaken, '83-'86 T-birds with the 3.8 had the C5 tranny which isn't as strong as you'd need with a 5.0.  Again, though, you can obtain a used junkyard AOD tranny that will fit your 5.0 for pretty cheap.
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: BiscayAutomotive on March 29, 2005, 08:04:50 PM
As stated above the carb swap is easy, just another intake manifold and carb, replace the gaskets and away you go.  ebay would be the cheapest.

As far as the tranny goes, yes the C5 will bolt up to the 5.0, but it is not very strong.  I would suggest an AOD or a C4.  The C5 is basically a C4, but weaker, so if you use a C4 it will all bolt right up with no problems.
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: softtouch on March 30, 2005, 01:58:59 PM
I thought the only differance between C4 and C5 was the C5 has metric fasteners?
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: Tbird232ci on March 30, 2005, 02:22:10 PM
nope, the C5 has a much lower torque rating than a C4
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: Tbird 83 on April 02, 2005, 10:42:18 PM
But will the c4 last with normal driving for now as im on a budget for the time being. Since my v6 3.8L is now resting in peace and I couldnt find one anywhere I had to go for the 5.0L. Im hoping this was a good move. As for the transmission is there a big enough difference between the c5 and the c4?

Thanks again.
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: Tbird232ci on April 02, 2005, 11:21:00 PM
a C4 will hold up no problem, my buddy has one behind his 5.0 stang, and its his daily driver

as for a C5, it would work....but for how long is the question
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: V8Demon on April 02, 2005, 11:25:14 PM
I would not trust a C5 behind a 5.0.  I've seen it done in an old Bronco II.  The guy drove it around town for a couple of days easily enough without problems.  On his first trip on a major highway,  The Jersey turnpike,  he hit the gas to get on from exit 7 going north.  That's when that C5 went :toilet:
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: Tbird 83 on April 02, 2005, 11:31:00 PM
One last question, are the motor mounts for the v6 3.8L and the v8 5.0L the same?

Also what kinda of carb do u guys recommend.

Thanks again!
Title: Re: Tbird 83 v6 3.8L to V8 5.0L
Post by: 4thqtr on April 03, 2005, 01:07:15 AM
Quote from: Tbird 83
One last question, are the motor mounts for the v6 3.8L and the v8 5.0L the same?


Yes, the mounts themselves are the same (be sure you get solid ones), BUT the mounting brackets are different. The bottom brackets should be the same (make sure you match up which side is which since they are different), but make sure you get the top brackets from a 5.0 Bird or Cat since they won't be.