205 with a turbo 350 or 400???

[Patriot]

Hey fellas. I have a 1977 Blazer and want to switch out the 203 for a 205. I was wondering if they make a 205/350 turbo or 400 turbo for that year of Blazer?? If I have to go with a sm465/205 set up that would be fine also.

Thanks in advance guys.

[Critter]

I forget if the th350/205 or th400/205 was an option in 77 (I'm pretty sure it was), GM was kind of stingy with the 205s in that time frame as far as half tons were concerned. BUT there would be no problem swapping either combination into your Blazer if thats what you wanted. The th350/205 would be much easier to find and cheaper. One thing you would want to do is remove your drive flanges from the front axle (assuming you still have them) and put in a set of locking hubs to fully reap the benefits of having the 205 on the highway. The th400 setup will be pretty tricky to find unless you are willing to shell out a bunch of money on Ebay and pay shipping etc.

What transmission is in front of your 203 right now, a th350 I assume???

As a side note, the only transfer case available in 1980 was the np205 regardless of 1/2 ton, 3/4 ton, 4 speed, auto, etc. Then in 81 a lot of the 1/2 ton drive trains started getting the np208. This info has been useful to me when searching over the sea of vehicles in the salvage yards being as 1980s have a pretty unique grill configuration.

[Patriot]

Originally Posted by Critter

I forget if the th350/205 or th400/205 was an option in 77 (I'm pretty sure it was), gm was kind of stingy with the 205s in that time frame as far as half tons were concerned. BUT there would be no problem swapping either combination into your Blazer if thats what you wanted. The th350/205 would be much easier to find and cheaper. One thing you would want to do is remove your drive flanges from the front axle (assuming you still have them) and put in a set of locking hubs to fully reap the benefits of having the 205 on the highway. The th400 setup will be pretty tricky to find unless you are willing to shell out a bunch of money on Ebay and pay shipping etc.

What transmission is in front of your 203 right now, a th350 I assume???

As a side note, the only transfer case available in 1980 was the np205 regardless of 1/2 ton, 3/4 ton, 4 speed, auto, etc. Then in 81 a lot of the 1/2 ton drive trains started getting the np208. This info has been useful to me when searching over the sea of vehicles in the salvage yards being as 1980s have a pretty unique grill configuration.

Yes sir, my truck has the original 350/203. It has the factory 400 motor also which is pretty cool but I don't like the 203. My other trucks have the SM465/205 and Dana 60/14 Bolt but I would rather not steal from those beasts.

[Critter]

I have never made the swap myself, but I am 99% sure if you get the factory GM 205 adapter (the part between the tranny and transfer case) and a 27 spline input NP 205 it should be an easy bolt in. The only other thing to consider is the output yokes/flanges of whatever 205 you get might not match up to what's on your 77. However they can be mixed and matched pretty easy for almost any configuration.

[1bad71]

I'm not sure if it was an option from the factory?? But you can get the 205 with the male 27 spline input shaft and adapter for the th350. Or also can get the female 32 spline for the th400. Either way they will bolt up in your application

[Jim85IROC]

205/400 combo was very common in 1 ton trucks, so you shouldn't have any trouble finding the parts you need.

[65ChevyUtah]

Some of the th400 from the early 70's are the same for 2 wheel drive as 4 wheel drive. So if you find a 205 and adapter for the th400 you can just take the tail off the 2wd th400 and it bolts right up. This is what I ended up doing and it only cost me about $400 for the whole setup.