Engine and transmission swap 88 Blazer into my 72 K10

[duke10]

I have found a 5.7 v-8 and 700r4 out of an 88 Blazer that seems to be in really good shape. Motor and transmission have just over 5,000 miles since a major rebuild on both. How difficult would this swap be going into my 72 K10? My motor is really tired and my transmission could use some help also.
Any obvious issues or anything I would need to look out for?
My truck never had air conditioning and the Blazer does, will that be an issue?
Thank you for any help.

[57taskforce]

The easiest way is to use all the accessories on the current engine in your K10 on the new engine. What do you plan to do for the transfer case? Your K10 should have an Np205, which in my opinion is the best transfer case GM has ever used. Advance adaptors makes 2 kits to bolt the 205 to the 700R4. One uses a couple inch spacer between the transfer case and transmission, the other replaces the output shaft on the transmission and does not use the spacer. If the 88 is a 1 piece rear main seal block (it should be) with fuel injection you may need to rig up an electric fuel pump setup if you’re going to run a carburetor in your K10 as the later blocks aren’t *usually* drilled for the fuel pump pushrod. The boss is still there but not drilled, it can be drilled but requires engine disassembly to be done correctly. This is just a few things off the top of my head. all that said I’d be Leary of the 700R4, they aren’t particularly strong in stock form and don’t have the best reputation for longevity.

[duke10]

Thanks, that information about advance adaptors is very helpful

[52napco]

Keep the TBI and put the pump in your tank..I have a TBI on my 72
Blazer and it's the best thing I ever did to it..15mpg and very driveable.
And keep your 205 transfer case !!!

[cj847]

If you have access to the whole Blazer, get the computer, wiring, gas tank and install them all in your truck and keep the efi.

As far as getting it in the truck, the only issue I can think of is moving the transmission cross member and shortening the drive shaft and an adapter for the transfer case if you want to keep you 203.

I am not sure the cost of changing a vortec to carb, but a carb, intake, and distributor are a minimum.

[57taskforce]

That’s not likely a vortec, that’s more likely a tbi. vortec is 96+. I would leave the 205 mounted in the factory location and mount the engine crossmember where it lands depending on the 205 adaptor setup you run. Cheaper and easier that way in my opinion. The K trucks mount the engine in the rear position so there’s always plenty of room to move forward a bit.

[truckster]

Originally Posted by 57taskforce

If the 88 is a 1 piece rear main seal block (it should be) with fuel injection you may need to rig up an electric fuel pump setup if you’re going to run a carburetor in your K10 as the later blocks aren’t *usually* drilled for the fuel pump pushrod. The boss is still there but not drilled, it can be drilled but requires engine disassembly to be done correctly.

If the boss is drilled there will be a block-off plate where the fuel pump would mount. Even if the boss is drilled, the cam may not have a fuel pump lobe. The L31 I put in my Blazer had a block-off plate but I had to change the cam to get the fuel pump lobe.

I like the sound a Quadrajet makes when the secondaries open, but for ease and reliability the TBI is a good choice.

[gmc684x4]

My experience with fuel injected 350 motors if they have a block off plate there a 4 bolt main

Rebuild engine cam will have a fuel pump lobe
Ord engeering will have adapters as well looking at going that route with a 4l80e to np205 tcase