taylor8907

Hey everyone, im sure this has been beaten to death and I know ive read so many pages everything is bleeding together so I wanted to ask a few questions before my Dad and I start on this conversion.

We have a 66 lemans convertile we are going to be converting. Originally we planned to go with a 6.0 and a 4l60e but after some research it seems those two are not compatible. The car currently has an older 350 chevy so were hoping to give it a good bit more power hence the 6.0. My question is mainly what transmission will fit with the least/no modification and what motors we could hook to that tranny. Were not looking for a wheelie popping dragster by any means but would like it to have some power because why the hell not right

Thanks in advance for any advice you guys can offer

-Allan

bczee

iTrader: (12)

The 4L60e will bolt up and work. But depending on what year and application it was from will either bolt right up or need different spacer or a flex plate.

For a daily driver and ease of installation, go with the 4L60E.. You will need a tuner to make programming changes in the ECM (also depends on while one you have). The 4L60e should fit with min Trans Tunnel modification.

Best bet is to find a engine and trans that are already together from the same Car/Truck.

Really suggest you read through the FAQ for the A-Body build threads. But keep your question coming... try and keep them to one subject or area.. you will get better direct answer and not a whole book as an answer.

BC

PowerAdder

What trans is in the car? You could just use that?

taylor8907

Thanks, im looking over those threads as we speak...One thing i know is that we dont want to use the current trans because we do want the overdrive.

Is there a 6.0 that comes with the 4l60e or would i have to look at a smaller engine?

EDIT: Also, i do have a TCI FAST Tuner for the transmission. The harness will work on the 4l60e 4l65 4l80 and 4l85. But i did see a thread on here where a guy dropped an LS3 into a 67 GTO with a 4l60e. So im trying to help myself as much as I can and see what modifications had to be done for them to bolt up.

Thanks again for any advice you guys can offer

taylor8907

anyone? Or should I be posting this in a different area. sorry im new :/

bczee

iTrader: (12)

I am no expert on what came with what. Just not something I keep up with. .. maybe someone else will ping in on this..

Sorry..

BC

taylor8907

NO problem, what kind of power is your LS1 putting out? just curious as its currently got a 350 in there i dont really want to go to the 5.3 and downsize, id like to keep it at least at the 5.7 but they are harder to come by than the 6.0

bczee

iTrader: (12)

Taylor

The last time I got it dyno/tuned, it was 330 RWHP, all it had was a cooler T-Stat, Headers and CAI.. I have since upgraded from a stock LS1 cam to a 03 LS6 cam and springs. But have not had it retuned as it seem to run well enough and the Tuner said I should be ok for now.

BC

jwatts

iTrader: (4)

I went with an LQ4 in my 66 Chevelle. I ended up going carb'd and put a 200-4r trans in. If I were going with a fuel injection I would stick with a 4l60 or 4l80. The 4l80 would work with the 6.0 with no changes. The 4l60 would need the flexplate setup off of the 5.3 or 4.8 to work with the 6.0 (assuming it is a truck engine, not sure if it is different on the car engines or not). The only other thing would be if it were one of the earlier 6.0s. They had the flexplate spacer made onto the crankshaft, so the flexplate would be spaced out too far to work with a 4l60 made for a Gen3 engine. If you do end up with a 6.0 with the long crank, the 4l80 or any of the older GM trans will work.

Also, the flexplate from the 6.0 will have 2 sets of torque converter bolt holes on it. They are both TH400 patterns. You can bolt an older dual pattern SBC flexplate to the 6.0 flexplate using the TH400 bolt holes. You can then use the TH350 pattern bolt holes on the SBC plate to slot the 2nd set of holes on the 6.0 flexplate to make it a dual TH400/350 flexplate.

Edit: I went with the 200-4r for a few reasons. One of the reasons was fitment. If you put the engine in with 1" setback mounts (which leaves the bellhousing in the stock location) you can slide the trans crossmember back to the TH400 spot and not have to modify the crossmember or driveshaft from what you have with the TH350.

oldgoat69

A 4L60E will work just fine with an LQ4 or LQ9. I used a 2003 LQ4 with a 2005 4L60E. Just make note that the transmission plug on your wire harness will need to be repinned from the 4L80E pattern. When you get to that point I can provide the correct pattern.
jwatts is right on the bolt pattern for the converter. You can also slot the holes just like some OE flex plates. The center register is created off the crank so you will nt have any alignment issues.
This combination works great as a driver. If your plan is to beat on the car use 4L80E.

ijimmy

ly6's did come from the factory with 4160e's , in fact its very common . They also came with 4l80e's , which is a much larger transmission , a-bodies have an issues with driveline angles , so the 4l80 is a much harder install , lots of cutting and welding involved with a 4l80 . I have a 64 chevelle with an ly6 and 2004r , you can use your stock crossmember and driveshaft with this combo