LSx '85 C10

Hello all, I recently got an aluminum 6.0 long block out of a Tahoe Hybrid, the cylinder wall have some scratches but don't look too deep , I'm hoping to build a 402 with this block, I would like to do an LS7 top end but I'm not sure if this would be over kill or even necessary I'd like to see 600fwhp or about 500rwhp

I'll post some picters of the cylinders once i get it home and see what you guys think of the scoring on the walls.

I need more help on heads and cam choice than anything right now.

This motor will be going in an autocross 85 c10 swb with porterbuilt suspension.

My thoughts on the build were

TSP forged rotating assembly
11:1 Compression
Ported and polished LS3 or LS7 heads
FAST LSXr 102 intake
Nick Williams DBW 102 TB
1 7/8 longtubes
4" single exhaust

FastKat

iTrader: (10)

I just did something like this. I used an Eagle forged crank + rods & ARP rod bolts, Clevite bearings, and a Mahle 4032 flat top piston set. I assembled the shortblock myself and all my clearances were well within spec. I think I paid $2,100 shipped for the whole rotating assembly. It was a good deal and I'd buy those same components again.

The one thing I would suggest is going out to 4.030 on your bore and make it a 408. There's really no reason not to unless you're using FI or nitrous. I've seen a lot of discussion about 4.030 being too big for these sleeves but the loss in sleeve wall is really small. We're talking a difference of about .012 off the wall. That's the thickness of about 4 human hairs. I believe ERL offers that package.

BKsNHRA

iTrader: (4)

A guy down here just did a 416 with stock ls3 heads and a 230-242 113 cam in a vette. He made 475 with it. He has since decided to go with ported ls3 and a bigger cam. Hes looking to break 500 rwhp with it. That first setup got him close. The car traped 127 in the quarter spinning.

LSx '85 C10

I wasnt sure if you could take that mich out of the sleeves. I was looking at doing roughly.the same components for my rotating assembly . Did you have yours balanced?

I was looking at RHS small bore LS7 heads , they dont come assembled though but they're not terribly expensive. The only thing im not sure about is cam choice I think the best thing to do would get a custom grind from one of the vendors.

BKsNHRA

iTrader: (4)

Tha wasent mine. Im in the process of doing a ls2 402 myself for my car. It will be balanced. The most I think you can go with the ls2 aluminum is .030 over to make a 408. As far as cam I would recommend either martin at tick or Geoff at EPS. They think a bit differently when it comes to cam specs but both of their stuff works well.

LSx '85 C10

So is the ls2 and the truck 6.0 the same exact block? Who would you recommend for machine work? I havent been able to find anyone solid in Phoenix. I always end up hearing something bad about everyone. Do you think the small bore ls7 heads would be too much gead for the motor?

BKsNHRA

iTrader: (4)

The truck 6.0 can be bored out more. The knock sensors are in different locations. Im not sure on the ls7 heads as I have no experience with them.

FastKat

iTrader: (10)

I think you're fine taking that much out of the sleeves. Like I said - 4 human hairs is not that much!

Yes, I had it balanced. You pretty much have to have it balanced.

I'm not sure how much farther out you can take the truck 6.0 block but you can probably take it out a little farther - how much is debated. A search should get you good and confused!

If you already have a GenIII 5.3 (it looks like you do) then the iron block would be cheaper and easier. It would be about as heavy as the block in your truck now, but you would not need to relocate the knock sensors, buy a new front cover + cam sensor, or a cam sensor extension. You would still be able to run LS3 heads and an LS3 intake with the larger bore.

LSx '85 C10

Any other suggestions on the build?