chris99gmc

What's up ya'll. It's been awhile since I posted. I need some help with trying to decide which route to go with for two of my builds... I have collected the majority of the parts for my 370 that I'm assembling right now. I already have a 408 built, which i've been considering going with a different heads/cam combo because I feel it has alot left on the table from a power perspective.. Being a chevy/LS builder with multiple unfinished projects has quickly turned my garage into a hoarding grounds for parts. I'm at a crossroads on which heads to use for my 370 build. Here's the details:

LQ block .030 over
Stock gun drilled, balanced crank
Forged H-beam rods
Weisco -11cc dished forged pistons
VS 7875 .96a/r Turbo, 2 wastegates, 1 bov, FMIC
T-56 Magnum 6 speed
Ford 8.8 rear end LSD
vehicle: 93 Toyota 2wd Single cab short box Pickup. 2600lbs Street/Strip
Depending on what heads I go with, this should yield around 9.5:1 SCR.

in the Garage/boxes, I have:
-stock 243 heads, 64cc, reman castings, valve job w/ sodium valves
-stock 823 LS3 heads, 68.5cc, brand new castings w/ sodium valves
-Ls6 intake w/ 92mm 4 bolt TB adapter
-Ls3 intake with 92mm TB
-LS6 cam
-LS9 cam
-Aftermarket cam spec'd at 239/242 649/600 lift 111+3 LSA
-Aftermarket cam spec'd at 242/250 650 lift 112 LSA
-PSI 650 polished beehive springs and BTR 660 Platinum springs
-Stock blue Ls6 springs, stock yellow springs
-uninstalled Trunion rocker conversion with bare L92 and Bare Ls1 rocker arms
-new Ls9 mls head gaskets

other build:
LQ block .050 over(414ci)
forged 4" SCAT crank
Forged I beams
Forged Protec/Autotec .045 flat top Pistons w/ 5cc reliefs
SCR 11.5:1 on pump gas. I wouldn't mind dropping the compression and/or stand alone fuel n2o setup.
currently has MS4 cam in it with rigorously hand ported cathedral heads. cc'd at 218int/81exh milled @63cc chambers w/ basically untouched bowls and blended seats. Weiand/Holley LS1/LS6 aluminum manifold Ported to 92mm with a FAST 92mm TB.

The n/a motor was originally built for a street/strip truck to run on spray. The heads that I threw on there were what I had at the time. They yielded too high a SCR for me to have enough courage to run it on the bottle with pump gas. (Although I've still considered it many times, I'd rather either bring the SCR down a bit or run it on better fueling to make it worthwhile).

I'm all for going with the parts I already have to try to make both of these setups the most optimal. Although I DO have the consideration of selling the LS3 intake and L92 heads for a pair of cast TFS 220 cathedrals in the back of my mind as well.. so that might be something I may consider.

Kfxguy

iTrader: (1)

1) I'm not too sure what the real intention of this thread is for, but i'll take a stab at it. I think its purpose is to let everyone know you have all kinds of parts laying around and to make us jealous.
2) The only question I see id what heads should you use on your 370 (ls3) build. Why would you even ask that? the ls3 are the better heads, arent they?
3) If i'm reading between the lines (i'm just guessing here because the only thing you were specific about was all the parts you have) correctly, you might be trying to decide what motor combo to go with? Thats easy to answer. Turbo motor.

chris99gmc

Just to be clear, I'm looking for honest opinions from anyone with knowledge or experience from doing similar builds - not out here to make anyone jealous. If that was the case, I have plenty of other cars and parts I could post pictures of instead of what I listed. But I'm not into that.

I originally purchased the L92 Ls3 heads, because like you, I thought they were better than the cathedrals. After talking to a few guys and reading more into which route the go, my opinion has swung the other direction towards cathedrals being better for my turbo setup. The difference between the two builds is that the 370 is being put together as we speak(goal is to have it in the truck and running by the end of the year) while the 408 is already in my other truck and running. I'm looking to make the most I can out of both, that's why I'm posting here. I've had multiple people offer me advise and suggestions on which direction to go with both builds, which has swayed me back and forth more than once. I'm just to the point I need to make up my mind and roll with it. Any help and suggestions from anyone with knowledge and experience will certainly certainly considered and much appreciated.

Kfxguy

iTrader: (1)

Was making a joke about the jealous bit.

Honest opinion. I don’t know, I’ve never tested both heads back to back. But what I’ve seen is the cathedral may have more bottom end tq. In a 2200lb vehicle, I think it wouldn’t be noticed if you lost it and went with the bigger heads. Plus turbo. I honestly don’t think either route you go with the turbo that you will say you should have done it the other way. And think about this, if by chance you do, how hard is a head and intake swap? That’s my honest opinion. Just get that mug together and running. Then dial it all in and see where you are at.

chris99gmc

What are the specs on the cam and heads you're running on your build?

Kfxguy

iTrader: (1)

I have 243 heads that I ported. Flow in the low 300’s on the intake and around 220 exhaust.

The cam cam is a summit stage 1 ghost cam, 222/233 on a 115 lobe separation.

Ls7colorado

iTrader: (3)

All I know is I wanna drive that toyota pickup when your done with it, I dont care witch heads you chose lol

chris99gmc

haha. No doubt it's going to be a fun little sleeper. I can't wait until its done. It's already a fun truck to smash around in as it is with the 5 speed and 22re... I did a Lexus Ls400 brake conversion, 25% larger bore master cylinder, front and rear swaybars and staggered 18" mustang torque thrusts. This little thing is begging for some serious power.