Sorting Out 2010 GM V8s ?

[PA41]

I was looking at a new GM truck today and it had a 4.8 V8--also looked at a 5.3 V8. They didn't appear to be the same line of engines. The 5.3 looked similar to the old SBCs with a Vortec head, but the 4.8 had a different head. Did GM get a different engine other than the evolved SBC for the 4.8 motor?

Thanks

Pa41

 

[joeyp]

The 4.8 and 5.3 are identical with the exception of crank, rods and pistons. They use the exact same block, heads, intake, oil pan. They share nothing with a Gen 1 sbc. I have a 5.3 sitting on an engine stand that im putting into my 35 ford, i also have a 400 sbc sitting next to it and they are not even close to the same.

 

[eyesore]

Yeah... in V8's I'm pretty sure GM only makes LS motors now. They are distinguished by having the exhaust ports equidistant instead of the interior ones close together like the older V's. LS motors also have different looking valve covers if they are visible & not under plastic covers.

ISore

 

[PA41]

Thanks guys--just what I needed to know. So the old SBC is gone..

PA41

 

[Tripper]

So the old SBC is gone..

Nope... they live on in old cars & junkyards all across the land! [cl[cl[cl

BoB

 

[rockabillyrat]

the 5.3 is a nice engine. i never see that many problems with them at work.

 

[RPM]

The 4.8 and 5.3 are identical with the exception of crank, rods and pistons. They use the exact same block, heads, intake, oil pan. They share nothing with a Gen 1 sbc. I have a 5.3 sitting on an engine stand that im putting into my 35 ford, i also have a 400 sbc sitting next to it and they are not even close to the same.

What about transmission bolt patterns and front motor mount patterns. Would the 5.3 bolt in where a 350 came out?

 

[Tripper]

What about transmission bolt patterns and front motor mount patterns. Would the 5.3 bolt in where a 350 came out?

RPM,
My 700R4 bolted right up to my new LS3 (6.3L). It had one bolt hole that did not line up but that was it! Not absolutely positive but I believe most GM trannies will bolt up.

BoB

 

[joeyp]

What about transmission bolt patterns and front motor mount patterns. Would the 5.3 bolt in where a 350 came out?

The only special part you need for old school tranies is a crankshaft spacer that moves the flexplate out .4 inches. You can even use the 4l60e's flexplate you just have to oval out the bolt holes slightly. They make motor mount adapters so the engine will bolt right in place of a gen 1 sbc, they run about $60. If you want to go even more old school you can even run a distributor.

 

[jfg455]

just dont drill and tap the hole at the 2 oclock position on an ls motor. Not unless you want a bunch of fluid leaks! a 6.0L flex plate (flat style) has the right bolt circle for older tq converters. You will need the adapter that goes behind it. if you want to oval the converter holes then you can run the dished (4.5,5.3, etc) and just run the adapter on the outside of the flex plate.