Best choice for engine project?
im also not a fan of using the converter boxes. never used them but its one of those things i dont believe in using unless you have too (like if it was 2007, and you found a 5000 mile ls7 from a totaled c6z and you wanted to use that motor in something because new gm crate engines are ridiculously high priced) you have plenty of easily accessible 24x options available in 2022
the 10 bolt with 3.73s you may be ok with since you are staying auto but be mindful of this. if you go above 500 rwtq, so any bore size larger than 4", you may be starting to test the limits of that 10 bolt a little bit. the 402 option i think will probably net you about 450-470 rwtq on a mildly to medium built setup. any mildly built lsx 427 with a 4.125 bore will be about 510-525 rwtq.
Last edited by Floorman279; Oct 9, 2022 at 07:15 PM.

01CamaroSSTx is right the 10 bolt is a weak link probably OK for driving around and may live for a while but a replacement would need to be planned.
My 91RS & 99T/A both have Hawk's 8.8's and am happy with them. ABS works normal etc for 99 T/A. Happy with both 8.8's etc.
A friend has the aluminum housing MWC 9 inch and its awesome. Would probably want a MWC 9 or maybe the Dana 44 (need to educate myself on the Dana).
Can one do a Watt's link with an S60?
Last edited by 99 Black Bird T/A; Oct 9, 2022 at 11:25 PM.
In my opinion, the best, most fun street combo that even wife will enjoy is the biggest displacement your budget allows with good flowing small port high velocity heads and MILD cam that’s easy on valvetrain and not fuel-smelling.
It will be far more enjoyable as a daily. The hell with peak hp number on dyno that cause smelly exhaust, tuning issues, potential valvetrain issues, damaged lifters or at the very least periodic valve springs replacements.
That said, in short term considering cost and your parts on hand, if the LS1 is in good shape, I’d go with option #1, but would use smaller chamber TEA 706 heads over AI 241s for higher compression.
You already have tons of hands-on experience and probably know better what is best for you and your wife.
Last edited by cino; Oct 10, 2022 at 09:59 AM.
The 263,000 mile LS1 is very healthy other than nasty sounding piston slap on cold start in the morning. Sounds like a diesel briefly. Wife, stepson & myself allow the Z28 to warm up (slap go away) before driving. Burns half a quart of oil ~2,000 miles. Valve stem seals never replaced. Holds oil pressure like new with the thin Mobile 1 synthetic 5w-30. Previous owner had various gaskets & crank seals replaced, new oil pump & new timing set etc installed by Subaru dealer (former GM dealership). No leaks etc.
The AI 241's have the welded high compression 58cc chambers. I think on a stock LS1 good for ~11.65 compression. The TEA S2's 5.3 probably about same after being decked and cleaned up for use.
Adding ~1.5 pts of compression over stock on a high mile LS1 w/piston slap? Ring wear concerns?

Im not a fan of the 383ci motors. They can be hit or miss. Ive seen some sbe LS1s put down similiar numbers/e.ts as a LS 383ci setup... its not the same bore and stroke as a old school 383ci small block chevy. I think that may play a role with it. Who knows ?
The Best V8 Stories One Small Block at Time
Adding ~1.5 pts of compression over stock on a high mile LS1 w/piston slap? Ring wear concerns?
If you plan to refresh one of your engines, selling good running LS1 and rebuilding LS2 makes more sense performance and budget wise.
Read GM rated LS1 rings at ~ 300,000 miles durability. With 263,000 miles on the clock, probably to late for H&C.
@PREDATOR-Z said in #57 of highest-mileage-cam-swap-poll
"Miles are not the only determining factor, but the health of your motor.
My advice before camming:
1- Leakdown test
2- Compression test
Only based on the results then make a decision."
new LS2 block
SRP 11.5:1 - 2618 pistons
Callies Compstar 4" crank & 6.125" rods
Improved Racing windage tray
PRC LS6 ported heads
Fast 92 intake / Nick Williams TB
CamMotion LLSR 236/240 - .640/.615 - on 113 + 3
2.73's sounds like great mpg. What's the highway?
Also yes, I do like the 2.73 on the highway, although I have no numbers as to what my mileage is.
Hiltsy855, sounds like a sweet LLSR 403 set up with quality parts that makes excellent numbers! Getting 500+ whp from ported LS6 heads is outstanding in my book. Do you have a build thread? Would enjoy taking a look etc.
Lots of stuff being kicked around here. Any of the narrowing down process happening yet?
You put some great choices up in the poll. I would have a tough time with it.
My choice of camming a 430HP LS3 was just to keep it simple and enjoy the ride, but messing with the Lingenfelter box apparently has its issues with some here.
And putting in a 24x reluctor would un-simplify things a BUNCH.
This is a great thread!
The GMPP LS6's are obsolete compared to newer offering. However, the old LS6's with big ~245cc intakes ports would work for my fun 427 LS build. Upgrade to an LS7 top end later to make more hp if desired.
#3 the 383 is so KISS (keep it simple stupid) it has real let's just get this done appeal. Allows for selling of lots of parts too. Just drop off the T/A's old LS1, EPS cam and Summit stroker crank at engine shop and come back for a nice 383 ready to swap into the 02 Z28. Would need rods & pistons etc. It would make decent power but nothing to write home about.
And putting in a 24x reluctor would un-simplify things a BUNCH.
GM offers a 24x 6.0 iron block that's pretty sweet. Probably should have added it as an option except as a purist I like aluminum block V8's, nearly as exotic where I grew up as a Ferrari v12 engine...
Lot folks don't want the LPE box for different reasons. These seem most common:
1) The slight delay on start sometimes as the box syncs
2) Or to avoid the delay doing the double key bump.
3) Botched install
4) Horror stories (due to botched install usually)
5) Worry about added complexity if repairs needed
Talked with my local shop about swapping reluctor wheels from 58x to 24x they were less than enthusiastic due to labor intensive. My 99 T/A has done well for five years with the LPE 58x to 24x box. Trick is have a quality install and keeping box away from heat. T/A has had zero issues with the LPE box. However, there's always the long term concern about any special electronics over time. Probably ought to pick up a spare box just in case.
For the record, I'd worry more about an MSD box dying and stranding you than the LPE's box. Have seen several MSD boxes do that over the years.
It also seems like with the wonderful GM crate LS engines available a great time to discuss too.
Last edited by 99 Black Bird T/A; Oct 12, 2022 at 11:44 AM.
simplifies things as far as ecm communication and retaining stock gauges and what nots ( I un simplified it by going stand alone ECM which makes me wish i had just done an ls3) I like number 4 as to me this is simple. turn key, no questions and good power out of the box with room to grow. scope creep here but one could just run a newer ecm and a holly prodash and skip the reluctor wheel issue...
That said option 5 of a 427 in a camaro puts a grin on my face and was my original plan for my bird. either of those are good choices in my book
I'm a big fan of this as well, It just makes sense if you're going to use it on the street all the time, and especially if you spend much time above 60 mph.
Blackbird Do you still have the stock converter in it? Leave it in there a little longer and try this first, It would get incredible mileage, The loose converter is going to kill the fuel mileage and every time you are on a hill barely moving at 3,000 RPM and you're being passed by a kid in Honda That's laughing because he thinks your car is broken you are going to hate it
If you don't have an ET goal in mind or a sworn enemy that you're always trying to beat from a dig a big stall, low gears, and a big cam is still a big waste on the street. This is why I have two cars to play with, one with 4.10 and one with 2.73. The 2.73 car is much quicker and stealthier on the street, much easier to get the power down usefully.
Put a crate LS3 in it and use the SDPC PowerMax cam that works with the stock LS3 springs, It's a 204/222 112lsa and It will make more power everywhere You want it with a baby smooth idle.
Blackbird Do you still have the stock converter in it? Leave it in there a little longer and try this first, It would get incredible mileage, The loose converter is going to kill the fuel mileage and every time you are on a hill barely moving at 3,000 RPM and you're being passed by a kid in Honda That's laughing because he thinks your car is broken you are going to hate it.
I don't think a nice tight Yank 3600SS w/3.73's will drive quite that loose in a 4th Gen. A friend has a Yank 3600SS w/3.73's in his 00 B4C Camaro and it drove pretty well in traffic. He's let me drive his car couple of times. My 72 vette has a nice tight Yank 3,200 (no lock up) TH400 w/3.08's, drives very close to stock.
Gas mileage takes a hit that's true.
That 1st that 2nd shift w/4L60e is like going off a cliff....6500 rpm in 1st to like 3300 rpm in 2nd...that doesn't matter normal driving...but when it matters...it really matters. Gears and converter really help.
Definitely agree easier to get power down with 2.73's & 3.08's etc on the street.
Last edited by 99 Black Bird T/A; Oct 12, 2022 at 02:36 PM.

























