I just bought a 72 chevelle and im wanting to do a 6.0/4l80e swap in the car and i cant seem to find a conversion kit that uses a 80e. And i would like to no if the trans tunnel has to be cut up? Any info on this conversion would be really helpful. Thanks!

 

It needs to be opened up about 2" down the top center of the tunnel. Or do like I did and cut the old one out, buy the Chris Alston tunnel kit and do it after the trans is in. I used a brp hot rod kit and spaced the trans up about 3/4" from their "kit" crossmember.

 

They don't make a kit per say, but a drill and drill bit away from makin it work

 

What kind of conversion kit were you looking for? Just a tunnel kit? Mounts, wiring, etc?

Jon
PSI

 

I had a 4L80E behind my old SBC. There was no need to cut the trans tunnel. There were a couple tabs on the trans that I ended up cutting off, and the rear coolant line is a PITA. Otherwise no problem.

Troy

 

Its where the engine sits. an LS does not sit the same in relation to a SBC. It pushes the trans back more, making the bell housing hit the tunnel, the trans cooler lines are not accessable, and you cannot reach/plug in any of the sensors on the drivers side.

 

I just put A 6.0L/4L80E in my 71 velle using the BRP mounts, they do make the engine sit high. I did have to cut the tunnel to get the drive shaft angle right...Others have said that the BRP mounts Do sit the engine high. Other mounts may work better...BUT, the PS pulley cleared the steering box and also the tie rods....I wouldn't use the lh8 pan tho, it still sits to low.. I had to add a skid plate to protect it. And Iv already hit it a few times....Like said above, I too had to space the tranny up on the crossmember from them... I used all the trk accesories and even the intake....I put a thunder racing cam, yank 3200 stall in it and made 391hp/385ftlb torque. It hauls ***...
Rick

 

I was wanting to no if they made a mount and cross member kit that allowed you to use a 4l80e with out cutting anything. I no the 4l60e cross member will bolt to a 80e i just didnt no if there was a kit that used different mount points to lower everything so the trans wouldnt hit the tunnel.

 

If i use a th400 would i need to cut the tunnel. Idk if i want to hack the car up it has no rust anywhere on the floors, any of you have pics of your trans tunnels after you have modified them?

 

Cutting the tunnel isn't really that bad. Measure twice, cut once. Not having any rust will make it easier and help with having a better final product. Once it is patched back up, smoothed out and painted it can be made to look stock.

 

Using a th400 would sort of be working backwards, what with the lack of overdrive and all. A 4l65e would fit without cutting wouldn't it?

 

4L60E will fit with little to no problems. Depending on the placement of the engine you may need to make some crossmember mods.
I second the pan suggestion. Don't waste time trying to make it work. There are too many options that take all of the trouble out of the equation.

 

If the body bushings are good and you use adapter plates that do not push the engine back from the stock bellhousing location, there should not be any need to cut the tunnel. 4L80s have been installed in Chevelles many times. The main case is roughly the same size and shape as the TH400, but the 4L80 is longer. You may need to dimple the tunnel in a few spots, but that's about it.

The Edelbrock adapter plates put the LS engine in exactly the same spot as the SBC was in relation to where the bellhousing mating surface is. A lot of people push the engines back so they can use the f-body pan, but this causes problems with the tunnel and also when the transmission has to be removed for servicing.

Andrew

 

Think im going to order the edelbrock kit and try it out. Im a little nervous about this but i really want a ls2 in this car so i have to try! I just bought the car so i have to get my money rite again before i can buy the motor and tranny.

 

I started with the original TH350 in the stock location, bolted the engine to it, and welded in Moroso solid mounts where they came to rest on the frame. I also used the aforementioned Edelbrock adapters. The engine has a corvette bat-wing oil pan and GMPP Front Drive (PN 19155067) and everything fits fine.


After doing all this, however, I lucked into a T56.

Leaving the engine in place, I dropped out the TH350 and all of its plumbing, and put the T56 in place. I needed an aftermarket Trans mount and custom drive shaft (arriving Friday from Action Machine, in South Bend IN - great tech support). The T56 required a bit of banging on the tunnel for certain items to clear. This was especially needed near the back, where the reverse lockout solenoid came within 1/4 of a floor pan cross brace.

One thing to try: it's easier to bolt the trans to the engine with both out of the car, obviously. But, if you're like me and leave the engine in, the top two bolts from the bell house to the engine can be a royal pain to get in. I got this done by getting the bottom four done and lowering the trans to as far as it will go (still supporting back of trans with lift). Be careful not to dump fluid all over the floor. It's not fun.