Ok since you are staying NA then I definitely recommend cubic inches and higher compression especially looking for torque living below 5k rpm. In 3-5 years if you consider the blower then at that point sell your heads and get a set with larger combustion chambers to lower compression if needed. Not worth sacrificing compression ratio and the entire setup now for something that may or may not even happen in 3-5 years. Maximize your current setup now for the heads/intake you have. If buying a rotating assembly anyway I'd go with a 383 at 11.5 to1 static compression or so with those heads and enjoy the heck out of it.

 

All kinds of possibilities here.

LS1-LS6=346 or do a 4 inch balanced rotating assembly and make a 383

LS2, LQ4 and LQ9=364 or do the 4 inch balanced rotating assembly and make a 402

LQ4-9 blocks bored to 4.030 bore with LS1 crank=370 or do the 4 inch balanced rotating assembly and make a 408

LS3=376 or do the 4 inch balanced rotating assembly and make a 415

And they good news is that they will all make power once you add forced induction to them.

 

I am not sure what heads etc. the OP is looking at but now knowing the 3-5 years later part. LS1 Block and stock crank is perfectly fine. You should look a doing a Procharger vs a Blower. You can pick up a used Procharger head unit or even new. Then piece together the rest of it with ebay parts for about half the cost of a new blower or Procharger kit.

"5K RPMs one a dyno and maybe a few times a year at the drag strip." Even more reason not to waste money on a forged crank or even another block.


What are your goals with the car?

 

I'm rolling the dice on an LS1 crank in my 370 build. I'm not making upwards of 900hp so I'm not really that concerned about it but when I start spraying 200+ shots on the motor the thought will be in the back of mind. "Is my cast crank held in by stock main bolts gonna hold up!"

 

Mamo Motorsports 220 heads
Mamo Motorsports LSXR 102 intake

Procharger or turbo is not going to happen. I live in AZ, and drive the car every day. AC functionality is a requirement.

 

I am going to do a 370 stroker on my LS1 block (This is personal preference, I do not want the stroke longer than the bore), setup to be 10:1 - 10.5:1 with the MMS heads, in case the Magnuson 2300 happens. That will give me forged pistons, rods, and crank. Depending on the cam that Tony specs, I should be in high 400's RWHP and mid 400's RWTQ. If I get the Maggie, I will just have to keep the PSI at 6-8.

We will see what my finances look like in 3-5 years. Maybe Maggie..... maybe Darton sleeved 427.


Thanks for everyone's inputs.

 

"Procharger or turbo is not going to happen. I live in AZ, and drive the car every day. AC functionality is a requirement."

You can keep a/c with a turbo or Procharger.

 

but the AC won't work for **** in AZ summers.

 

Says who? What does a procharger have to do with that?

 

Where are you getting the 370 rotating assembly with a 3.903 bore? I really don't understand why you are afraid of stroke on something that's not going to turn over 5k rpm. Plenty of 4" cranks being spun to 7000 rpm or even more if the top end/cam is good enough.

 

why not?

 

Correct you can keep A/C with the Procharger kit and some of the single turbo kits out there.

 

The Procharger kit requires the fan assembly to be changed to one larger fan, which compromises air flow through the AC condenser. I have talked to AZ desert residents that had the Procharger kit, and stated that the AC does not blow cold during hot summer months.

 

That's because you're strictly thinking of the stock Procharger fan stuff that is crap. What many people do is switch to pushers, something like twin Derale 16925's which are fantastic pushers and will keep the car cool and the AC working.

 

I haven't really looked for a 370 kit yet. I just know that K1 has a 3.9" LS1 crank.

I am not saying I will not go over 5K. I am just saying that the vast majority of the time will be under 5K. If I have a lot of fun at the track, I might go more often.

 

I will have to look at that.

 

May need custom pistons for that application.

 

Would a Procharger have any effect on my choice of rotating assembly? i.e. 3.9 vs 3.622 stroke... 3.898 vs 3.093 bore?

 

Forged would be nice over a stock cast crank given that its got the additional load of the crank, but bearing choice and clearance is more important. I wouldn't even sweat the 4 inch stroke crank as BCNUL8R said, assuming the clearances are good and its assembled right.

 

I have a bad case of "if stock comes out, stock should not go back in". So, we will see what a 370 stroker kit ends up costing, and go from there.