C20 Longhorn tranny swap

[Jesus5150]

So my wife smoked my original th400. I unknowingly bough a bop th400 and (what I'm assuming is the tail piece) is like 4 inches too long on the bop. So I unbolted it thinking I could swap tail pieces, and no go. The shift is one long piece. (I'm new to transmissions so this was all news to me) now I'm thinking I can just replace the front driveline with a shorter one, but have no clue on what information I need to go shopping.... I'm assuming just spline count and length. Can anyone advise?

[hugger6933]

BOP stands for Buick, Oldsmobile, Pontiac. The transmission will not fit your truck. what your gonna need to look for is a Chevy pattern short shaft TH400. did you buy the trans from a yard or something like that, that maybe you can swap out with them? On the other question about pulling the guts out and just changing them from one case to the other, well it can be done but not by regular guys with regular tools. You would need a few special tools to even do that, and those tool the cost may be prohibitive. Jim

[Jesus5150]

Why won't this work? I Bought a conversion plate for the bell housing. Isn't it just a matter of finding the right drive shaft now? It's 2wd. Not sure if I said that.

[hugger6933]

if you got the plate and are in search of a drive shaft by all means proceed.

[Jesus5150]

You say it won't work, then you say proceed... If it won't work I'd like to know why...

I'm new to this and searching for information. Not just "won't work"

[MARKDTN]

By the time you buy an adapter and a shorter driveshaft, you are half way to the cost of a rebuild on a TH400. You can do what you are doing-but why?

[jjzepplin]

I am with some of the other guys. Rebuild the th400 short shaft. It fits your truck already with no modifications, is original to your truck, is stronger than the BOP, and you won't have what looks to be a pieced together-god knows what is in there type of truck. Sometimes we get in a mode where we think "just one more modification and I will have this licked" then you look back and you have modified everything and spent more than you should have and could have just fixed what you already own. Just sell the parts you have acquired and rebuild the Chevy trans - easy peasy.
Don't get me wrong- I am all about modification if it makes your truck better. Do you even know if the new trans works?
Look at my signature, Lots of mods going on there. Blazer was totaled and rebuilt with leftover parts and the SWB had all it's parts scavenged from the Wrecked Blazer that was built as a rock crawler back in Cali in 1998.

[hugger6933]

I'm sorry for my short answer. I am usually known for my noel like answers to the point some have complained about them.But those same people also turned around and asked me for help, go figure. That is my fault from what I gathered from the first post info wise, You were dealing will very little info on this transmission. Then I posted a quick response to do what I thought was help to set the thing back towards the right path. The thing you have will work but like said above you might have been better off than getting an adapter and another drive shaft paying to find another short shaft TH400 or having yours built by a trans shop. I hope all this confusion can be put behind us and I surly didn't mean to mislead you or try to sound like someone who was smarting off to you or show any disrespect. Jim