JDH70508

I have a 1978 International Scout that I want to put a Gen III engine and 4L60e transmission in. I got a good deal on what I though was a 5.3L with all the wire harness and PCM including Electronic throttle control. When I pulled the heads off to have them ported I realized it was actually a 4.8L. I am still trying to decide what to do and am trying to keep this build on a budget but would like to get 350# of torque out of it. The guy porting my heads has offered me a set of ported 799 heads he had lying around for $500. He is going to put the LS7 springs in it. I have been tossing the idea of buying a 6.0L shortblock but trying not to break the bank. My idea is to get the 799 heads and put a radical cam that would get the most out of this 4.8L. In the future if i am not satisfied and can raise up enough cash i will swap all the parts on a 6.0L shortblock. I guess my main question is what cam can i put that will work in both the 4.8L and in the 6.0L to get more torque out of each. I am going to get a local pro to tune on a chassis dyno.

dmelvin

iTrader: (8)

The 4.8 is just a de-stroked 5.3.

You can grab a stock LS1 crank, throw some new main bearings in it, and have a 5.3.

Don't know what your budget is, but it's an option. Hell, I have an LS1 stock crank that I'd sell you for $150 shipped. Probably needs polished by a machine shop, or at a bare minimum inspected (I'm not anywhere near one, or I'd have it done for the higher resell value), or a new one from TSP is $700

A radical cam is going to kill your torque.

What does the scout weigh?

slammedsilvy

iTrader: (3)

You're going to want a smaller cam to keep that power down low. Something like the 212/218 comp camp, TU0 cam, or the Isky triple 12 cam. A big cam will make it scream up top, but won't help the low end where you want it.

DR132

what are you planning on doing with the scout? if you're just looking for something to move it a 4.8 will do just fine...they're not entirely dead down low so unless you want a serious hot rod or 4x4 it should be sufficient...also whats your gearing?

TXSZ66AVLANCHE

iTrader: (7)

With a 5.3 crank you will also need rods, 4.8 rods won't fly with a 3.622 stroke 5.3 or ls1 crank.

SnakeOiler

iTrader: (6)

Look for a 'towing' or 'RV' cam. They are made for creating extra torque.

zero2sixT

iTrader: (4)

You could run a rotating assembly from a 6.0 or a ls1 to make it a 5.3.

It's prob a lot cheaper to find a lm7 5.3 shortblock.

andrew383

iTrader: (14)

Like stated already just swap the crank if you want a 5.3..

As far as heads go id keep the stockers and swap in the larger intake valve's,smooth the intake runners and light porting on the exhaust along with a .025 mill..
IMO the 799's will be to much for what your wanting to do..

dmelvin

iTrader: (8)

You're right, forgot about rod length, Used crank, used rods would run around 300 bucks. I think you can generally get a 5.3 longblock for around $500

old motorhead

iTrader: (10)

You need positive manifold pressure. It would take a "magic" cam to increase your low end torque more than a little bit. Ported heads won't do it either. However, a used MP112 Maggie on top and you've got tq out the wazooo with your 4.8L. I've seen the complete kits sell for as little as $2K.