A bump for me ...

 

Dont have the part number for the spacer, but if you talk to a GOOD parts guy he can locate one for ya.

So you are going for the 80 swap huh? Now that I have "most" of my issues worked out I am happy. I should be headed to the track within the next two weeks or so to get some e.t. info.

Keep us posted on your progress.

 

Yup ... I think so .. The only problem I'm going to have is modifying the crossmember. Would the heavy trucks crossmember fit right in place of mine or do I have to modify mine?

 

Modify yours.....pretty sure the bigger truck x member wont fit.

 

Flyer you could get crazy like I've done and run 4.56 gears it's kind of fun having 2nd,3rd and 4th gears bark the tires.2700rpm at 70mph does get a little noisey,with loud pipes.Actually 2nd gear spins the tires about 10 to 12 feet and the others bark the tires.

 

Maybe I should go with 3.90's afterall.

Are you running a stock 80e with a shift kit or what?

How did you do your crossmember? Got any pics of it, before and after maybe???

 

I wouldn't bother with 3.90s,I'd go with a set of 4.10s to compensate for the tall first gear,that combo will workout with about the same 1st gear ratio as a 4L60 with 3.42 gears.

 

Flyer...I believe that Parish8 won't mind if I post his link for ya. I am also being torn by the 4L60E or 4L80E dilemma...and have been researching it a bit. Hate to throw good money after bad by trying to stay with a built 60E...

I also have been in touch with Hughes and they responded with the following (I'm sure they won't mind my sharing...):

"Sounds like a pretty cool project you've got going on there. Those LS1's
make awesome amounts of power, very easily. I'm always impressed with them. You're definitely on the right track, the 4L60E's will tear apart left and
right with a heavily modified LS1 engine, especially in a bigger truck like your Yukon. The 4L80E is the best choice by far. Our Street/Strip 4L80E (part# 25-1) is good for about 1000HP, no problem. It'll will bolt right up to the LS1 bellhousing, as long as you use our flexplate, which has the holes drilled for the 4L80 E converter, and an adapter sleeve due to a difference in pilot length. The crossmember and driveshaft will probably have to be modified, as well as the computer programming as you're probably aware. You might want to contact Arizona Speed and Marine (480) 753-0208) for a little help if you need it, they've done lots of Chevy truck swaps and we've built a lot of 4L80E's for them. They might be some help. If there's anything I can help you with, feel free to email me, or call me at 1-800-274-7223. Thanks, Matt Leischer Hughes Performance"

 

Since I'm not "handy" with a torch, I'm looking for an easier approach.

I also had the thought of buying the cross member for a HD and install it directly into our trucks. In example, I would think that I can just buy the cross member for a Yukon XL with a 6.0L and bolt it in. I guess I need to visit the dealer and take some pics & measurements.

 

Good info!

That link is almost just what I needed.

The Yukon XL has the 65e though, so that won't be any help to you. I'm just worried now that a converter is going to cost me an arm, leg, and a left nut. I'll bet the converter is going to cost as much as the trany almost.