oxrabidus

I am curious to know if the 4.8L LR4 V8 will accept LS6 heads? and a LS crank and such? will LS type parts work with this engine?
Thanks.

oxrabidus

No one knows? or no one cares to answer dumb question?
The reason I ask is because it is a gen III engine, and it probabaly has better fuel economy than any gen I engine...
Thanks.

SSC

Honestly dont know. You may have better lcuk asking the the LS fourm.

five7kid

iTrader: (14)

Let's just move it there.

SheldonZ28

iTrader: (1)

Yes it will accept LS6 heads, but it will lower the compression ratio.

It will accept an LS crank, which would bring displacement to 5.3L. LS external parts & most of the rotating assembly transfer. Pistons and rod's are different due to stroke & Bore

oxrabidus

Oh...sorry bout that...but thanks for the info...
by the way...
I saw these ported heads that are for the 5.3L tha flow 290 cfm at .550 lift on a 3.78" bore...now that with a GM stage II cam and a couple other things how much power will it make, just a guestimate...and how much power could I put on with the stock internals, if I was to use boost...and will it bolt on to a T5 (it will be a modified T5)?
Thanks!

socal

for the cost of making it fit a t5 your better off geting a t56 for cost, strength, sixth gear

i thought the 4.8 had to small of a bore for the bigger ci heads?

oxrabidus

what would have to be changed for the transmission, either make a T5 work, or put in a t56...
and if I am not mistaken, the LR4(4.8L) and the LM7(5.3L) have the same heads...

socal

Just not sure about the heads and can't do the research right now.
You can get a stronger, better built, stock lsx t56 or use a built t5 that might be as strong as the t56 and have to change the bell housing, and mclode is the only one i know of who make one to fit, but there not cheap, and you may need to change the flywheel and clutch as well. All in all more money.

oxrabidus

well, dont you need a new crossmember and driveshaft and stuff for a t56 swap? I will pay a little extra just to keep it as easy as possible, with as little custom fabrication as possible... how much would the bell housing be? and what clutch would I have to get...because I am gonna get the astro performance super t5, supposedly holds up to 500 ft/lb.

oh and the heads and block are the exact same, only difference is the stroke...just read it on the GMPP Catalog...

five7kid

iTrader: (14)

Driveshaft is the same.

Is that "holds up to 500 ft-lbs" the same as the way GM rates transmission?

oxrabidus

What do you mean?

And I thought you would need a shorter driveshaft for a six speed?

five7kid

iTrader: (14)

GM runs a transmission at the rated torque for 24 straight hours. That's a lot different that putting 500 ft-lbs on a transmission and it doesn't break.

Well, you can put a 4th gen T56 transmission behind a TH700 or T5 in a 3rd gen, so I guess not. I had a thread not too long ago about aluminum driveshafts, I posted some pics there.

oxrabidus

Oh well i dont know about how they do it, i guess i have to ask...
but how much would the bellhousing be?
and i am still curious to know how much power it may make with a couple things added...head cnc porting, gmpp stage 2 cam, and msd ignition, and FAST intake(if it will work with those heads...)
thanks.

Air_Adam

The T56 uses the same driveshaft as the T5 and 700R4. The T56 setup from an LS1 will bolt right up to the 4.8L block and everything should fit up the same - only thing I'm not sure on is if you'd have to have the T56/5.7L flywheel rebalanced to use on the 4.8L.