Bezzerwizzer71

Im looking for some information about what is the best internals for 500+ hp.

Ive seen many kits for sale but i want the best internals.

And also ive been searching for good valve train specs for a 10:4 compression.

any comments helpful thanks

96capricemgr

iTrader: (1)

Based on what you wrote you are a year out from even considering starting this project.
The displacement has a lot less to do with output than most newbs assume. Heads a part you didn't even mention has a LOT to do with power.
10.4:1 is stock compression, a built NA LT1 should be 1-2 full points higher

TravisMcGill2000

iTrader: (2)

Really any forged rotating assembly will hold 500 hp. I see your new to the forum. My advise is to do alot of research. Find a combo thats been proven and copy it. Far as building a stroker just make sure you have all the supporting mods. Good heads and cam to take advantage of the extra ci. Also a lt1 can run 12.5 compression on 93 pump gas. 10.4 is stock compression and its to low for na and to high for boost. I would look into ai or le for topend packages.
Ps. Do lot of reading or you will need up spending alot of $ and be unhappy. Good luck

bufmatmuslepants

iTrader: (3)

Also need to consider budget. Too often guys come on here and say "I have $3000, I want a 500rwhp stroker, will this cast eagle crank work? I want to use the stock heads". Doesnt work like that. Anything over 400 flywheel horsepower, you need a forged crank. Flirting with 400, you will be OK with a Scat cast crank, but do NOT get an Eagle cast crank, do a quick search for "eagle cast crank failure" and youll see why. Have you ever driven a 3300lb 400rwhp car? Thats probably more than enough for you. A stock 350ci bottom end with a good head/cam package like AI200cc or LE2s will give 425rwhp, spending the extra $2000 for the forged rotating assembly and $1000 for machine work will only net another maybe 25-35hp.

Do you have bolt ons already? You need long tube headers, and offroad Y pipe, and a cold air intake.

Did you factor in suspension $500, clutch $300 (or stall $800), rear end $1500 used, driveshaft $300, injectors $300, and a tune? Have to have a tune anytime you affect valve timing (cam). Not a Hypertech, a REAL mail order custom tune $200, or a dyno tune $400. Stock suspension is stamped steel and will flex even with stock power and sticky tires, causing wheel hop, which is the #1 killer of the stock "made of glass" 7.625 inch rear end. Need rear LCAs, and a torque arm. Also need a torque arm relocation mount $250 to get the torque arm off of the tail of the transmission so you dont break that. You also need sticky tires $400, if you cant put the power to the ground you wont go anywhere. You get that taken care of, you need a clutch or a stall to hold the power. Auto, the stock 4l60e needs rebuilt to handle the power $1000, M6, you just need a clutch. Get all that taken care of, you can start looking at heads $1500-2500. Heads make power, not cubic inches. Cubic inches support big heads, more cubes, the bigger the heads you can use. Too big of heads on small cubes and you would need lots of RPM to get the velocity back up through the ports (PCM limit is 7100, a 23x/24x will need all 7100 on a 350), bigger cubes doesnt need as much RPM to get the same velocity. Want to stay small cubes and go over 7100rpm? Need an LS1 PCM swap $500-1000. So you get heads and a cam specced for YOUR setup, say $2200 AI200cc heads and cam, http://advancedinduction.com/LTX/AiLTxCylinderHeads.php. Now you are at a crossroads, are you happy with 425rwhp or do you want 450-470 or are you going to spray? Either of those you need forged pistons (forged for spraying, new pistons if you are getting a new crank), if you replace the pistons you need to get it rebalanced anyways, and the stock rods become a weak link, so you get new rods. You can stay 355 with forged rods and pistons and the stock GM crank will NOT break, but if you are already in there and want those extra 30 cubes and 30hp, $800 or so for a forged crank. Anything over 360rwhp needs bigger injectors, $300. Stock cast Mahle pistons are high quality, and can handle a 150 shot of nitrous. Cheap chinese aftermarket cast are weaker. Stock GM cast crank can handle 700hp, cheap chinese will break at 400. A stock rebuilt bottom end with stock crank, rods resized for ARP bolts, and stock pistons can handle 600hp (ask bowtienut, he has this setup with a 100 shot and AI200cc heads pushing a 4000lb B body in the 10s)

See how it adds up?

Now what do you want again?

sweetbmxrider

iTrader: (13)

I can sell you my complete motor and you'll have great internals and lots of power. It went 10's in my car. Drop it in and go fast!

SS RRR

iTrader: (2)

Rear wheel or flywheel HP? Flywheel is easily obtainable with the right heads and aggressive cam. Rear wheel is a completely different story.

350 groundpounder

iTrader: (5)

Thats impressive that the stock bottom end can hold 600hp with arp rod bolts. LE1 heads and a decent cam and you got a quick street car. Didn't realize that a 383 is that more expensive than a 355. Good info.

bufmatmuslepants

iTrader: (3)

383 is only more expensive than a 355 if you reuse the stock crank for the 355, if you use a forged crank for the 355, they are the same price.

96capricemgr

iTrader: (1)

And the stock crank is bulletproof so buying a forged 3.48" stroke is wasted cash unless liteweight