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What seems to be the weak link in the high rpm LS Engine?
I did a little digging around looking for a way to make my LS1 scream and the weak link appears to be rod bolts. The rest of the information was people telling you not to build it because torque is awesome.
Hot Rod's 1200 hp 4.8 had ARP rod bolts, as well as enlarged top ring gaps, new lifters, a comp bumpstick, better springs and a larger throttle body and intake, as well as stage 1.5 ported heads. The stock 120,000 mile crank, rods, and pistons were used.
Basically, the typical high-RPM formula. Then add boost, subtract traction, equals giggles!
NGTD wrote:My dad used to have a 283 in a 38 Chev coupe and he used to turn it to 7500.
The 4.8 would be similar displacement - The 5.3 is almost identical to the old 327 and some purists will swear that the 327 was the best SBC ever made.
The new 5.3 has nearly the same displacement as the old 327, but with a longer stroke and smaller bore.
Hot ticket would be to combine a cheap 4.8L motor, a used LS1 5.7L block and pistons. Bore and stroke would then be almost exactly the same as the old 327, but all aluminum and with the LS-heads from the 4.8L.
Lots of folks insist the 5.3L motors will bore out to 5.7L though as well, which might mean all you would need is a 4.8L, some pistons, and a gasket set.
Gen III/IV engine bore and stoke combos 
3.779" bore combinations
3.898" bore combinations
4.000" bore combinations
4.065" bore combinations
4.125" bore combinations
Keep in mind that Hot Rod got well over 400HP BEFORE the turbo madness. Not bad for 293ci with a cam and minor headwork.
Reading this has made me want to defile my nice blue RX-7. (not to be confused with the other 3)
Doesn't help that I found a 87,000 mile LS1/T-56 combo 20 minutes up the road for $3,000 and will include everything I want from the donor car.
BUY NOW!!
In reply to Greg Voth:
Offer $2500 cash- then BUY NOW!!!
Positively none of this thread makes it easier to NOT buy a Roadmaster for a new daily... 
Jesus H., where do you live? Is it rusty (it doesn't look like it, and my current one is). I could totally bring that up from the states...
Sorry for the late response.. i live in Texas (as far from Canada as possible) and the car was repainted around 10 yrs ago. No rust that i have seen and i have been over it pretty well.
MrJoshua wrote:In reply to Greg Voth:
Offer $2500 cash- then BUY NOW!!!
Believe me I want to. I doubt they would take it being a Junkyard and all. They did however knock $700 of the list price if I purchase it as a combo.
I should be able to sell the motor and related stuff out of the RX-7 to Zero out the purchase. I'm pretty sure I could throw it in there with some left over bolts and a welder making it cost nothing 
It doesn't help that I dont exactly have $3,000 sitting around especially after entering the Chumpcar Race at Sebring, and trying to get that car ready. Plus I still need saftey gear.
