Help me choose a short block... 38X aluminum vs 40X iron?
 

Earlier this summer I bought Chris ARE 385's old 5.3L H&C set-up... here the details of the set-up...

5.3L ARE ported heads 2.02/1.57 valves
Dual Springs (987's)
298cfm @.600 lift intake
228cfm @.600 lift exhaust
227 intake CC's

After 30K miles with 250+ passes, 100+ dyno pulls, and 200+lbs of NO2 the rings in my original 2002 Z28 shortblock are about ready to throw in the towel... the car is still running and still makes 415+RWHP... but I do not want to push my luck and would like the car to be 100% ready for next spring.

Here's what the car made on the motor after the H&C install and with a 100HP TNT ring kit...
http://solo2.abac.com/avigdor/temp/Z...s29%20copy.jpg

My objective with this car is to create a well balanced streetable package that is equally comfortable on the drag strip or Auto X circuit and I drive about 10K miles every summer. The rest of the car is pretty much setup as far fuel system, suspension, drivetrain and exhaust... I just need to get my engine sorted out :)

My dilema is between a 38X aluminum vs 40X iron short block... I would like to keep my existing heads in order to keep the cost down. I might be able to keep my existing cam with the 38X option but will for sure need a new cam if I go with the 40X option... Am I dreaming to think these heads will work with a 40X shortblock? Am I better to sell the entire H&C package and go with a new long block? I am not in a big rush as I live in Montreal and will putting the car into storage for about 5 months till spring...

I would like some suggestions on what I should do... my goal is at least 450RWHP and I would really like to see 500RWHP... I plan on spraying no greater than a 150 wet shot every once and while...

My budget for the shortblock is around ~$3500... thanks for your input!

I have an 6.0 block and an LS1 block that I can build and I'm torn between which one to do also. The only reason I'd prefer the 382 over the 408 is the weight of the iron block. I've worked really hard to drop weight off the nose of my car and sticking an extra 100lbs back in there would just kill me. I know the 408 will make more power, but on a solid roller 12:1 setup.... wonder how much difference there would be?

Would you be keeping your 5.3L heads? This is what is giving me a hard time... the weight does not bother me that much... and I would love the extra torque of the 408 :)

I'll try to keep mine for a while until I see how the AFR 225's work when they finally come out.

Do you think my heads would work OK with a 408?

I would have the chambers setup for a 4.030 bore and watch the compression ratio. Other than that I don't see why they wouldn't work for a mild 408 like you are wanting.

Thanks for the feedback... If I do decide to sell off the heads and cam and start from scratch, what do you think would be a reasonable price to ask for them?

LS2 blocks are avail now to make yourself a 402 all aluminum, but not sure about the cam position sensor issue yet :confused:

Todd what would your Lunati 408 shortblock run if I wanted an LS2 block instead of an iron block?

go with an ls2 aluminum 402 they are available just get the ls2 cam reground.

What about my heads and who is selling an LS2 package these days? And idea of price point? Thanks

Talk to Allen at fms he will be building some ls2 motors in the next couple months. You should just have to open up the combustion chambers to the new larger bore and the heads should work fine for a mild stroker motor.

The blocks run around $300 to $400 more than a new 6.0L block. I can get you a quote today and send you a PM.