8.1 vortec into 1979 k30

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77 K20

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1977
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K20 5" lift
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HT383 fuel injected
Search "Dirty Larry" on the other square body site. He's done exactly what your thinking. His thread will answer any question you can ponder.

I was going to say this. I read something like 33 pages of stuff on his blue truck and I thought he was doing it again on a Suburban. I read it on expedition portal though.

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yevgenievich

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Big blocks can get expensive. My tall deck 8.0l build cost me a small fortune. 8.0l was the gen6 with gen7 parts sprinkled on it. Rods and pistons are the weak points on 8.1l. Raylar heads supposed to perform very well from what I have seen.
 

forcruzen

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BRAD
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C10
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496
Did it....Love it.....Just took my first 8.1L for a long distance road trip. A few tips to follow....
search "dirty larry" like that one guy said
had original harness rebuilt but I still decided to do correct new harness from Howell Engineering.
Find a blown up 8.1 from possibly a van. That gives you all the brackets, pumps you will want if trying to get ac pump moved up since the gm parts numbers are obsolete unless you get lucky.
C10 old school headers do fit, original motor mounts work. Everything else from the past will not happen.
Whatever you think it will cost to do this just take that number X 2
 

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1984dually

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Danny
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1984
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C30
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8.1L
Did this swap in 2013 in my C30. look up 8.1 on here and it will come up. Swap is easier than a ls based swap. Just pullout your 350, swap over your flywheel/clutch/engine mounts and bolt it in. If you want air the frame will need notched or swap the van/medium duty truck stuff. One thing to remember is you’ll have to change everything on the front of the truck including the balancer. There is aftermarket stuff available. look up Amos Garcia on facebook. Makes some good stuff. Front crossmember will need a notch to clear the drivers side of the oil pan. Bigger radiator might be needed(used 6.2 diesel radiator). stand alone harness from Howell
 

Lu Blunt

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1979
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K30
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350ci
Slow train slow life but I’m back to work on the dually. Just can’t give up on the old truck. Got handful of parts for the swap and a list of things to order. The 350 looks small in the engine bay. I can’t wait for the 8.1. Anyone have a part number for the bolts that go through the bell housing and into the block? Thanks
 

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bucket

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I'm assuming the bellhousing bolts are metric and m10x1.5 thread. I won't take a stab at the length... that's too many assumptions for just one post, lol.
 

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