Starting the swap

[c1500]

Well i have had my motor for a couple months now just sitting in my shop. I have a few questions Where would be the best place to buy a gasket set for my 6.0 2001 lq4? i plan on just pulling the heads off, what else would be recomended by you guys to do? Where can i get the motor mount adapters? what headers will work out the best for putting this motor into my 91' fullsize 5 speed? anything other information will be appreciated. thanks

[LS1Nica]

Hey this question has been asked a ton of times but I guess I cant give you a few pionters. Is your truck a V8? You can get the adapter plates for street and perfomance. Have you decided what tranny you want? As far as engine internals go I cant help you there. I know about the swap cuz I did it myself. F-body manifolds are about your best option, but I heard about some people putting G-body LS1 conversion shorty headers. IMO shorty headers aint worth the money but whatever. If you want more info look at some of the older threads theres alot of good info. Good luck.

[1BADC10]

S&P adapters may/may not work w/o mods. There was a guy on PT that is going thru a swap into a 90's truck. He had to mod the S&P plates cuz it pushed the 5.3L too close to the firewall. They should work w/o mods if you flip the plates around. The reason for doing this is hole-placement for the OBS motor mount brackets.

I just dropped my 5.3L in my '86 Silverado this past week, and the BRP plates worked a lot smoother. PM me, and I'll send you the BRP URL. These plates were about $100. Bill Brewer owns the place. Or... you could check eBay for LS6 conversion plates.

The thing about using conversion plates is you may/may not end up working the motor in to get the proper "line-up" b/t mounts and brackets where the long bolt slides in. **NOTE: Engine lifts (or cherry-pickers) come in real handy for this.

Check the thread on this forum entitled "5.3L (LM7) Into OBS Silverado". I have pics there. BTW, wherever you get brackets from, make sure they're steel, not aluminum!

-Ron

[RedHeartbeat]

I've done two conversions in 92 and 93 C1500s and the mounts work great. Just remember that the pointed ends of the mounts point to the front of the engine and go in the front four engine mount holes on the block.

[NITROUS]

Here's a pic of my mounts. They are 1/4" Stainless. RHB, were you able to use the pair I made you?

[RedHeartbeat]

Yep, they are installed and working just fine. I ended up doing away with the countersink head type bolt and went with a standard bolt and washer. For the hole up top between the motor mount bolts I drilled a 1" hole through the engine mount cups. I also put two washers between the motor mount cup and your adapter plates. The other way would have worked but I was tired of messing with the countersink type screws. You could have just drilled 10mm holes through all the points on mine and they would have worked great. You can't tell the difference now that they're on the truck. The still look GREAT!!!

[NITROUS]

Great! These were my first sets and I can see alot of things I could have done different now. If I make anymore I'll just drill the holes.

[c1500]

ok so i guess just go with the ls1 adapter plates i found them on ebay, i curently have a 4.3l v6 with a five speed manual. i know of course to buy new motor mounts, and im guessing the 4.3 and the SBC should be the same mounts right? the tranny i want to use is the 5 speed that i currently have in my truck. i have been told that it will work just fine, but there will be one mounting hole that wont match up, and not to worry about it. the headers, i was looking at my stock exhaust manifolds, and thee was a crack , not on the manifolds, but on part of where it mounts to the motor.should i still go ahead and find a set of stock exhaust manifolds, or use some aftermarket manifolds made for a truck? any info helps.. thanks

[1BADC10]

If you're sure that the trans will bolt to the block, you should be ok. I can't recall what the setup is like in the 88+ model trucks, but I found out that my 86 frame brackets (V6) would not allow the Gen III motor to bolt in. As long as you don't have that issue, good luck.

Here's a shot of the V8 brackets for my style truck that I found at a salvage yard. They allowed for the engine to mount forward by approximately 4". Again, this is for the body-style prior to yours. Better to check than do what I did by trial and error.

V8 brackets mocked in place:


V6 mounting location:


V8 mounting location:

[c1500]

thanks for the help