Will any 350 fit?

[BabyBlueChevrolet]

I have a 1973 Chevy C20. I found a slightly used GM crate engine for sale for $3k and I plan on buying it and swapping it in. The seller says its got 4 bolt mains and a 1 piece rear main seal, and I believe mine has a 2 piece. Will this engine drop and bolt right in or are there any modifications or adapters that i need?

 

[75gmck25]

One piece vs two piece seals use a different flywheel, so try to get the flywheel with it.

You really need to get the numbers off the block and heads to know exactly what you are buying. If you need to do the swap quickly, buy a crate engine with as many matching accessories/parts as possible.

The engine will bolt into the truck fine, but may be set up for different accessories and other details. For example, there is the original SBC intake manifold you probably have, then the updated heads and carburetor intake bolt pattern from about ‘86, the TBI intakes that started in ‘87 for EFI, and then the Vortec intake bolt pattern from the 90’s. Parts are available to work with all of them, but it can get a little complicated.

 

[Rusty Nail]

If you manage to change out only one SBC, you'll be able to swap the next 1,000 no problem.

 

[idahovette]

Lotta money for a nonverified, used small block Chevy?

 

[CheemsK1500]

Like others said, be aware of the little details. Also make sure it has provisions for a mechanical fuel pump. If it doesn't you'll either have to retrofit an electric fuel pump system that works with your carburetor or just go ahead and covert to a TBI system.

Make a note of all the vacuum operated items on that truck such as brake boosters and automatic transmissions. You may need to make provisions on the new engine's intake to support these devices.

 

[BabyBlueChevrolet]

hmm, Im just gonna check compression on the engine and if compression is good im gonna get a new carb and distributor

 

[75gmck25]

Again, get the numbers off the engine and heads and post them before you start buying parts. Then you will get more specific advice. It will save you time, money and frustration.

 

[GTX63]

I have a 1973 Chevy C20. I found a slightly used GM crate engine for sale for $3k and I plan on buying it and swapping it in. The seller says its got 4 bolt mains and a 1 piece rear main seal, and I believe mine has a 2 piece. Will this engine drop and bolt right in or are there any modifications or adapters that i need?

The mounting hole locations on the small block chevy itself did not change. That is the short answer.

I have a 74 with the original engine, but my 79 has a 71, my 1970 has a 1982 motor, my 1980 has an 84, and my 1985 has a 1978. They all drop and bolt up the same.

The rest of my reply is opinion so feel free to skip it-
I bought a brand new "crate motor" for less than 3k, several years ago.
It was shipped to my door and had a warranty.
I recently contacted a guy on marketplace that was selling a brand new 350 crate motor, never installed, for $2200. I offered him $1500 and he took it. No guarantee but that was the risk I was willing to take.
If your seller can fire up the motor and let it run while you are present, that is a plus.
Also my opinion, but when it comes to driver quality, go to work Chevy trucks, 4 bolt mains are of no importance.