Engine swap advice

[Nate]

I have an 86 C10, it came with a 4.3; before I got the truck the previous owner swapped in a 305, (casting number makes it a 80-85). Something in the lower end gave loose so I would like to swap in a 350. Any advice and pitfalls to watch out for will be greatly appreciated and advise on where to get a new crate motor. It's a 80-85, 305, so I'm assuming its a 2 piece main seal, is it worth going with a 1 piece, and do I only need a new flex plate? I am fine with a 2 bolt main and am looking for reliability and drivability. Thank you for your help!

 

[C10MixMaster]

I have an 86 C10, it came with a 4.3; before I got the truck the previous owner swapped in a 305, (casting number makes it a 80-85). Something in the lower end gave loose so I would like to swap in a 350. Any advice and pitfalls to watch out for will be greatly appreciated and advise on where to get a new crate motor. It's a 80-85, 305, so I'm assuming its a 2 piece main seal, is it worth going with a 1 piece, and do I only need a new flex plate? I am fine with a 2 bolt main and am looking for reliability and drivability. Thank you for your help!

differences between a 1 and 2 piece rear main engine.
flex plates dont interchange between them
oil pans are not the same make sure you new engine comes with one if your switching
heads will probably use center bolt valve covers on a 1 piece rear main and a perimeter bolt valve covers on a 2 piece rear main engine and dont interchange
allot of 1 piece rear main motors are not machined for a mechanical fuel pump. if switching might have to go electric.
2 bolt mains are fine for most applications. 4 bolts are for nitrous ,superchargers and bragging rights.

 

[Nate]

Thank you, I have a lot of assumptions and I know those can get expensive. I think I am going to go with a long block with valve covers, timing cover, and an oil pan.

 

[Bextreme04]

Thank you, I have a lot of assumptions and I know those can get expensive. I think I am going to go with a long block with valve covers, timing cover, and an oil pan.

If I were you and you have room for it, I would find a 95-2000 GM truck/suburban with a 5.7 L31 engine in it. If you find one with a recently rebuilt engine and maybe a blown trans, you can get them dirt cheap for the whole truck. I would think $500 or less. You can sell the catalytic converters on them for $260 a piece and have a complete engine for free. Part out a bunch of other stuff on it and you can actually come out ahead. Pull the engine and strip the fuel injection off. The only thing you would need would be a Vortec carb manifold and maybe an external electric low pressure fuel pump. Everything else will swap right over and you'll be gold. Make sure to swap a melonized gear onto your old 305 HEI distributor or the L31's hydraulic roller cam will eat it.

You'll basically have a 4-bolt, hydraulic roller, vortec 350 at that point for next to nothing. When you are finished, drag whats left of the donor carcass to the local scrap yard and drop it off.

 

[Catbox]

^^^What he said.

That was the same thing I was going to say.

 

[TPISly-C10]

^^^What he said.

That was the same thing I was going to say.

same here!

 

[Ricko1966]

Me too. But are cats seriously bringing that much now? I was getting 130.00 for them years ago and the market fell out just like shred and all the other scrap.Ive got a dozen here, who's sold one lately?

 

[82sbshortbed]

I swapped my 305 with a BBC 454.

Go big or go home. Lol

 

[Bextreme04]

Me too. But are cats seriously bringing that much now? I was getting 130.00 for them years ago and the market fell out just like shred and all the other scrap.Ive got a dozen here, who's sold one lately?

I sold one off my 97 454 yesterday for $175 because I didn't want to bother shipping it. I was quoted $250 each by rockaway recycling. He offered me $400 for the pair, but when i went to cut one of them off the y-pipe it turned out it was empty. The honeycomb must have either disintegrated at some point or someone smashed it out before I bought it. Certain Honda cats(97-2001 Accords for one) can go for up to $900 for a single one. I suggest you find the serial numbers on those cats and get an online quote from rockaway. You can send in the quote request on your phone and attach the pics of the serial number. It took a day or two for them to respond with a quote.

 

[Hugeroost]

I swapped my 305 with a BBC 454.

Go big or go home. Lol

Hell yea !! I mean if your gonna go to all that trouble right, BB w intake/carb/headers your good forever

 

[RecklessWOT]

I sold one off my 97 454 yesterday for $175 because I didn't want to bother shipping it. I was quoted $250 each by rockaway recycling. He offered me $400 for the pair, but when i went to cut one of them off the y-pipe it turned out it was empty. The honeycomb must have either disintegrated at some point or someone smashed it out before I bought it. Certain Honda cats(97-2001 Accords for one) can go for up to $900 for a single one. I suggest you find the serial numbers on those cats and get an online quote from rockaway. You can send in the quote request on your phone and attach the pics of the serial number. It took a day or two for them to respond with a quote.

Jesus it's been years since I sold any. I think last time I got $60 each, that's crazy

 

[Curt]

Gm performance has a lot of different options for your budget and horsepower needs.I believe all the engines come with a warranty except circle track engines.

I went to a local Chevy dealer and in 30 minutes had a engine in the bed of my truck.