4L80 to 241 tall adapter

[AJs72K5]

Leaning towards a 4L80 in the build and attempting to avoid swapping out my straight trans crossmember.

Is there a tall 4L80 / 241 adapter? Haven't seen one in some basic searches...
Will the tall 400 / 208 work?
Is the bolt pattern on 4L80 different from the 400?

 

[sweetk30]

big oring lip is tiny bitt different size . easy to machine down .

search for the 4l80 to 205 thread TONS OF PICS AND INFO !

why not just make a bolt in spacer block to go from short to tall ?

 

[NorCalAnthony]

Some of the ’91 V2500 Suburbans had the 4L80E/NP241 combo from the factory so you might be able to find one online or at a wrecking yard if you’re lucky. I just bolted my 4L80E to my NP241 for a test fit and wound up having to use the newer style adapter from the donor truck (’01 Silverado 2500). My t-case was out of a ’90 Burb with the TH400 and the bolt patterns matched up perfectly for the trans and t-case but the little “feet”/bosses at the base of the adapter where it bolts to the cross member are offset towards the trans and wound up contacting the lower part of the 4L80E housing. Luckily the t-case from the donor (NP246?) had the same bolt pattern and was roughly the same height so I just used it instead. Hopefully that makes sense, if not I can try to snag a picture of the adapter if you want…

Edit: Just realized you were looking for a TALL adapter and I'm pretty sure the ones I have would be considered short versions. I don't think the taller version of the adapter would have contacted in the same place mine did so it may work for you. If not, SweetK30's spacer idea is probably going to be your best...

 

[thatK30guy]

Could use the short adaptor and get some spacers made to fit under the feet/tabs to rest on the crossmember mount.

 

[Cucv_M1008]

I might have a tall adapter.

 

[AJs72K5]

Thanks guys. Spacer sounds like the easiest / cleanest route.

 

[NorCalAnthony]

Just be sure to check out which one you're getting before you buy it. Here's a couple pictures of the TH400/NP241 adapter from the '90 Burb that didn't work because of "feet" contacting the back of the trans housing:



And here's a picture of the one that I wound up using from the '01 Silverado that bolted right up to both the 4L80E and the NP241 that has the cross member bolt holes more centered on the adapter:


Sorry for the crummy cell phone pics but hopefully they get the point across and will save you the same frustration I went through lol.

 

[sweetk30]

they do offer cast iron adaptors.

here is pics .

 

[sweetk30]

and for refrence here is a 4l80-205 adaptor . note : mounting feet rear facing to clear the tranny case . and there NOT the same length as older 400-205 round adaptor.

 

[thatK30guy]

I have that aluminum 4L80E/241 adaptor from a '99 truck if that will work for anyone needing it. Take it to PM's if interested since we can't do sales and prices out of the sale forums.