Engine/trans swap for 86 Blazer Question

[nascardude18]

Hello, I am from Canada, New Brunswick. I am getting ready to swap out a engine for a fresh 350 stock rebuilt and a 400 turbo transmission as well. The orginal trans is still in the truck, It was a auto- overdrive(still in the truck) and was bolted up to a 305 cid when I first got it. My question is, how much different is the other trans to the 400 turbo. I was told that it may be longer and have to make my drive shaft shorter. I have a 4 inch lift kit for suspension installed and my rear drive shaft is a touch short as it is. Is the 400 trans a bit longer then the stock 350 trans that came with the 86 Blazer full size?. I am also wondering if the transfercase is going to make a big difference as well. Any help would be great.Thanks

 

[u2slow]

If you are going from a TH350/NP208 or TH700/NP208 to a TH400/NP208, the lengths stay the same.

But, a TH350 in a '86 4x4 doesn't sound stock... makes me wonder if you have a t-case other than the 208.

 

[nascardude18]

How can I find out what I have , I am fairly upto par with mechanics, It has the over drive in it.Not sure where I can find that information, on the truck.So I guess I will have to find out what transfercase I have and what trans as well.What I know at this point is, It's a silverado K5 86 blazer, it had a 305 engine with polition control, now gone lol, any help would be great thanks... I will check on line for more info...

 

[nascardude18]

Does anyone have a blazer setup like I do, I was told it prob has a t-case trans case.My question is will the transmission fit up to the transfercase? or will it be longer or wider?Any help would be great .

 

[bigbadchev84]

i did the exact same swap as you did with no modifications, its a bolt up and go, i believe they are the exact same lenth it is the adaptor that determines the overall length. it sounds like you have a 700r4/208 combo. were you planing on using the same t-case with the new 400? or does it have a different one?

 

[bear76]

My LMC catalog helped me identify everything, best use for it so far.