Here's what I have.. Ls2 block and stock crank. I was curious.. If I sleeve the block with darton sleeves to fit a 4.125 bore pistons and buy 4.125 pistons with K1 h beam 6.098 rods could I use my stock crank? And what displacement would I be at? I know 4.125 is the ls7 bore. It's either sleeve the block or do a stroker crank.. I found a set of bnib piston and rods for 850$ shipped includes arp 2000 bolts. There's also a ls7 crank for 300$ but I'm not sure if the crank would fit in an ls2 block. I'm still leaning towards a good set of ls3 heads since I dont want to buy another manifold and **** My end goal is 850-950rwhp.. My drivetrain and fuel system will support it minus clutch. I'm not very familiar with building engines and just learning so any help would be nice

 

i'm looking to do a similar build, in my opinion i would keep the stock sleeves and just put the stroker crank in it, a 402 on 15lbs+ should make 900rwhp no problem. those heads are good but i would do some port work to the exhaust side because that is where the restriction is. A friend of mine running a 418 on 18lbs and 18*timing made 1000+rwhp,

 

I did plan on porting the exhaust side of the heads for sure. Any ideas for the displacement? Going from a 4.0 bore to a 4.125 and increased rod length.. I'm going to have one crazy ci lol. I feel a sleeved block would hold better than a stock sleeve stroker engine.. Could I be wrong? A 402 ls2 is bad *** set up for an ls2 And could get me to goal. It's really hard to pass on the deal I'm getting from old dude.. And the pistons are -32cc.. That just makes 9.5 if you was to directly replace stock piston/Rods on a ls7 with stock untouched engine. I figure with ls3 heads it'll be slightly higher

 

the ls2 block will hold 1200+hp i've asked this question once before. with the 4" stroke and 4.125 bore is a 427, with the 3.622 crank it would be a 387.

the LS7 crank will not fit in an ls2 block.... someone correct me if i'm wrong, and the stock rod length is 6.098, most aftermarket piston/rod combinations use a 6.125 rod with a .927 wrist pin

 

There -23cc pistons wisco K443x125.. The stock ls7 rod is 6.067 and the one provided with this kit is 6.098.. So the crank idea is out Of question... Also if I choose the 4.125 route wouldn't the engine rev higher.. Ls7's rev to the moon but they have a 4 in stroke.. If I'm right the more stroke the lower rpm's your engine will produce but the more torque you'll have down low and stronger powerband? The valve train has a lot to do with it as well.. Ti intake valves are nice! Again I'm an complete moron when it comes to this stuff at the moment. I came across some great deals but is there anything I should ask the guy selling these piston rods? It's hard to beat new blower piston/Rods with arp 2000 bolts for 850$

 

to be honest with you, i dont have any experience with the LS7 engine, just make sure that the new pistons are made for the longer connecting rod. the engine wouldn't rev much higher with the wider bore but u will be getting the extra cubic inches.

 

Thanks

 

Your best bet would be keep your stock sleeves and crank and rebuild with forged pistons and rods. Have the main caps doweled to keep them from walking and assemble with ARP studs. Pretty solid foundation - many have achieved higher power than you are looking for with this combination.

The LS3 heads will work well but will likely lift at higher boost levels. Aftermarket heads with a thicker deck will be a better option at higher power levels.

Assembling a 900 rwhp car is expensive to do right - there are many things beyond the motor that need attention and prices add up very quickly. If you are worried about the cost of a replacement intake - you are going to puke when you learn the total cost of what this car might cost. Putting together a 408 with a small shot of N2O is a far less expensive build. Won't get 900 rwhp but would can get you close to single digit ET's with the right combo.

 

I know the cost.. I done blew up my first s2. Nothing salvageable if you look at my build thread you'll see. I found a Callie's 4in crank for 500$.. But the guy sold the 4.125 bore pistons and Rods from under me.... So 402 is up in the air.. Only Gm bolt I'll be using is the lifter trays and timing cover.. Everything else will be arp

 

regardless if you are building a 1500 hp engine or something well under a 1000 hp we can help out.

We have plenty of packages that take the guess work away from you on what you need to make it work.

Our stock sleeve short block packages are some of the best in the industry and are very proven. Our V1 and V2 408 ci LS2/LS3 short blocks retail at 3650.00 with you providing a good core block and 4950.00 with us supplying the core block.

Let us know if we can help.

 

Thanks ERL . I hear about you guys from all over the LSx sites. I just recently purchased diamond pistons-10cc 4.005 bore.. Looking at a callies 4in crank as well.. I'm trying to figure out which Rods to go with. Wisco k1's , eagles,scat, or Manley? Keep in mind I should be 950ish rwhp max.

 

Stick with a stock stroke crank, just get it polished and balanced with the rest of the rotating assembly. Go with Wiseco or K1 rods. Total Seal AP rings steel top. You don't need a stroker motor to make big power. I'd go with cathedral port heads over rectangular also. Higher velocity beats higher volume IMO. Sell the ls3 intake you have and get an LS6, the ls2 intakes suck. Trickflow 220cc as cast heads with LS3 turned down intake valves and Ly6 inconel exhaust valves. Brian Tooley dual spring kit. Stock rockers with trunions. Morel street link bar lifters. Custom turbo cam matched to the setup. LS9 head gaskets & ARP 12pt head studs, or if you want to be cheap Alper Motorsports head studs or ebay KMJ's.

 

I thought about keeping the stock crank and just turn the boost up a tad higher, heard they can handle some power. Polishing and balance was a given for me. I was thinking a victory jr carb style intake since I have like 2-3ins of cowl over stock. Already have arp 12pt head studs from when I did h/c. I been seeing lsa head do some wonders but if I don't pull the trigger on a 4in crank and keep the stock that suffix some cash into the heads. The cam will be the last thing I buy.. I want it to match my entire set up.. Only thing about my intake it's already ported and I recently drilled a hole in it just after the TB for an remote iat sensor. Quick question about the heads.. I know the bigger turbo will make more power per psi than a smaller turbo because cfm.. Now with boost applications wouldn't the Rectangle ported heads work better since they have more Volume? The air is already pressurized so I wouldn't think volcity would be an issue.. Like if say my intake reads 14psi it's not going to force any more or faster into the cylinders.. So volume seems to take over? I can't really find a good answer to this.. I was thinking Ferra ss exhaust valves and intake with bronze guides. I still have all ls3 valves but I didn't think they would work well and really don't wanna risk it. I was told stock heads can hold up to 20psi before lifting but I don't think I'll be running near that boost to meet my goals. Don't think I should use these prc 670 dual springs with titianum retainers? I planned on doing the bearing upgrade on the rockers, All my hardend 7.4 push Rods are fine. Looking into moral lifters.. Still learning about all this.. All this studying during school kinda makes me annoyed to do research

 

https://ls1tech.com/forums/forced-in...cam-4l80e.html
take a look at this he did this for all under 4gs 562 boosted hp pretty crazy

 

That's pretty sweet but this is for a c6.. The cheapest turbo kit cost 5,800$ (with out shipping) and I have almost 2k in the fuel system Alone.. Another 500$ in upgrades with the turbo kit...I figure the clutch will be 1,600-2000$ I want one rated for atleast 1k rwhp.. Clutch can wait until I built the Engine. I shoulda just bought a fox body and built a drag car to suffix my need for speed.. The amount of cash I lost from my last engine and plus my engine cost I could had one wicked freaking ride... **** happens though

 

oh yea definitely woulda been alot easier and cost efficient but you committed might as well keep on going lol