Start with a L99 or a LS3?
10-08-2020, 11:59 AM
#1
Start with a L99 or a LS3? Looking to buy a L99 or LS3, either way I'm going to swap the cam, maybe the heads. For sure don't want DOD, on the fence about VVT if I go L99.
The question for all those who have already been there done that is,,, which way is cheaper in the long run?
Do I get a Junkyard L99 and do the needful (I'll do the work) or do I just start with a LS3?
Also I plan to run a 4L80E behind it as this is going into a 1st gen Nova. I know I need to cut tranny tunnel for either a 6L or a 4L but there is alot less cutting/fabbing with a 4L. Anything I need to be concerned about in terms of running a 4L besides the tuning? Like is the harness different between the 4L and 6L?
The question for all those who have already been there done that is,,, which way is cheaper in the long run?
Do I get a Junkyard L99 and do the needful (I'll do the work) or do I just start with a LS3?
Also I plan to run a 4L80E behind it as this is going into a 1st gen Nova. I know I need to cut tranny tunnel for either a 6L or a 4L but there is alot less cutting/fabbing with a 4L. Anything I need to be concerned about in terms of running a 4L besides the tuning? Like is the harness different between the 4L and 6L?
10-08-2020, 01:01 PM
#2
TECH Senior Member
If it helps any, the 6.2L truck engines (L92, L94, L9H) are near clones to the L99. The L9H and L92 have VVT but not DOD. L94 has both. Similar cams, compression, heads.
10-08-2020, 03:31 PM
#3
If you keep Dod, VVT, you are stuck running the later ECU. I don’t think those can run a 4L80. Not 100% sure.
The 6L80 is huge. And not the strongest. Also rather difficult to tune.
VVT is great, as long as you know how to tune it.
The L99 etc are likely cheaper, easy to convert. And if you have one in your hands, also easy to swap the reluctor to 24X and use the older 0411 ECU and harness which most certainly run the 4L80. Easy to tune as well.
Or, use a Holley Terminator. No reluctor change.
The 6L80 is huge. And not the strongest. Also rather difficult to tune.
VVT is great, as long as you know how to tune it.
The L99 etc are likely cheaper, easy to convert. And if you have one in your hands, also easy to swap the reluctor to 24X and use the older 0411 ECU and harness which most certainly run the 4L80. Easy to tune as well.
Or, use a Holley Terminator. No reluctor change.
10-08-2020, 04:27 PM
#4
G,
I'm concerned the truck intake will limit my top end and figured I'd go the passenger car route to save the cash associated to swapping the intake/inj/rails/tb. I also plan to gap the rings a smidge and hit it with a 150 shot as I'm removing my 9sec SBC and really want to keep it in the 10's. I'm not opposed to swapping the fuel delivery system if I can find the right price for those components and the cost makes buying the truck engine worth it. Is this the route most people are taking? I'm sure it opens up alot more buying opportunities!
I was not aware compression was similar, that is way good news thanks for calling that out.
Ron,
No way I'm keeping DOD, and I'm gonna lose the VVT to as it exceeds my tuning skills at this time. I guess I'll dig in a little more and see what I can find out about which ECM/TRANNY combo I might need. I currently have a P59 which is supporting my Gen3 with a 4L. Not sure I want to step back to a 24x, is there an advantage to doing that? I guess here comes the dumb question, I was thinking about cutting down the stock harness, can I plug that into a P59?
I'm concerned the truck intake will limit my top end and figured I'd go the passenger car route to save the cash associated to swapping the intake/inj/rails/tb. I also plan to gap the rings a smidge and hit it with a 150 shot as I'm removing my 9sec SBC and really want to keep it in the 10's. I'm not opposed to swapping the fuel delivery system if I can find the right price for those components and the cost makes buying the truck engine worth it. Is this the route most people are taking? I'm sure it opens up alot more buying opportunities!
I was not aware compression was similar, that is way good news thanks for calling that out.
Ron,
No way I'm keeping DOD, and I'm gonna lose the VVT to as it exceeds my tuning skills at this time. I guess I'll dig in a little more and see what I can find out about which ECM/TRANNY combo I might need. I currently have a P59 which is supporting my Gen3 with a 4L. Not sure I want to step back to a 24x, is there an advantage to doing that? I guess here comes the dumb question, I was thinking about cutting down the stock harness, can I plug that into a P59?
10-08-2020, 05:45 PM
#5
TECH Senior Member
As per Holdener dyno tests, the truck intake manifold is equal to the LS3 intake. If you have the vertical space, do not be afraid to use it. It IS a good manifold!
10-08-2020, 06:31 PM
#6
G,
I'm concerned the truck intake will limit my top end and figured I'd go the passenger car route to save the cash associated to swapping the intake/inj/rails/tb. I also plan to gap the rings a smidge and hit it with a 150 shot as I'm removing my 9sec SBC and really want to keep it in the 10's. I'm not opposed to swapping the fuel delivery system if I can find the right price for those components and the cost makes buying the truck engine worth it. Is this the route most people are taking? I'm sure it opens up alot more buying opportunities!
I was not aware compression was similar, that is way good news thanks for calling that out.
Ron,
No way I'm keeping DOD, and I'm gonna lose the VVT to as it exceeds my tuning skills at this time. I guess I'll dig in a little more and see what I can find out about which ECM/TRANNY combo I might need. I currently have a P59 which is supporting my Gen3 with a 4L. Not sure I want to step back to a 24x, is there an advantage to doing that? I guess here comes the dumb question, I was thinking about cutting down the stock harness, can I plug that into a P59?
I'm concerned the truck intake will limit my top end and figured I'd go the passenger car route to save the cash associated to swapping the intake/inj/rails/tb. I also plan to gap the rings a smidge and hit it with a 150 shot as I'm removing my 9sec SBC and really want to keep it in the 10's. I'm not opposed to swapping the fuel delivery system if I can find the right price for those components and the cost makes buying the truck engine worth it. Is this the route most people are taking? I'm sure it opens up alot more buying opportunities!
I was not aware compression was similar, that is way good news thanks for calling that out.
Ron,
No way I'm keeping DOD, and I'm gonna lose the VVT to as it exceeds my tuning skills at this time. I guess I'll dig in a little more and see what I can find out about which ECM/TRANNY combo I might need. I currently have a P59 which is supporting my Gen3 with a 4L. Not sure I want to step back to a 24x, is there an advantage to doing that? I guess here comes the dumb question, I was thinking about cutting down the stock harness, can I plug that into a P59?
10-08-2020, 06:41 PM
#7
TECH Senior Member
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10-08-2020, 07:21 PM
#8
I just built a cammed jy 4.8 with a on3 turbo backed by a 4L. The combo is in a '74 c10 sbss, easily my most favorite build. Love the way it runs, goes, and it's quite ish.. I thought about a holley dominator on the sbc and tossing a 4L with a box in it but I'm banking on selling the SBC/Tranny combo and getting into a another LSx combo for a reasonable price. I don't need to run into 9's anymore, too much of a hassle. And I like to build **** so here I go. If the SBC does not sell I'll stuff it in a Vega and send it down the track.
10-08-2020, 07:41 PM
#9
Of the choices you mentioned I'd go ls3. If at all possible do Corvette or even better cts-v front engine accessories. I have a first gen Chevy II wagon with a ls2 with GTO accessories and it is tight between the accessories and radiator. Do the 4L80e, much more proven trans.
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G Atsma (10-08-2020)
10-08-2020, 08:30 PM
#12
Of the choices you mentioned I'd go ls3. If at all possible do Corvette or even better cts-v front engine accessories. I have a first gen Chevy II wagon with a ls2 with GTO accessories and it is tight between the accessories and radiator. Do the 4L80e, much more proven trans.
what exhaust manifolds are you running? I was thinking CBR shorties. Was hopeful those would breath enough and let me get to my plugs. Be so nice to change plugs without needing to get phyc’d up for the one hour finger torture event.
do you run AC?
10-09-2020, 05:24 AM
#13
I have a set of Street & Performance 62-67 ls swap headers. They are very similar to the CBR mid length headers. I got a very good deal on them or otherwise I most definitely would've went with the CBR mid lengths. No problem getting to the plugs but I do have a Heidts mustang II style clip. As far as AC, I have a modified Alan Grove low mount. With that said if I did it all over again I would use the Holley mid mount accessories period. Slickest setup I've seen.
10-09-2020, 12:52 PM
#14
Good that you figured the E38 will support 4L80E. I’m just not up on those combos.
Got ya on VVT. We did a lot with that in the Dodges. I don’t know doodly squat on the GM stuff.
Might be best to get a PCM and an aftermarket harness. Just make sure it includes knock sensors and the factory narrow band front O2 sensors.
BTW, I hear ya on the hassles of running nines.
Your project will will be fun and run well!
Ron
Got ya on VVT. We did a lot with that in the Dodges. I don’t know doodly squat on the GM stuff.
Might be best to get a PCM and an aftermarket harness. Just make sure it includes knock sensors and the factory narrow band front O2 sensors.
BTW, I hear ya on the hassles of running nines.
Your project will will be fun and run well!
Ron
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epfatboy (10-09-2020)
10-09-2020, 01:56 PM
#15
Good that you figured the E38 will support 4L80E. I’m just not up on those combos.
Got ya on VVT. We did a lot with that in the Dodges. I don’t know doodly squat on the GM stuff.
Might be best to get a PCM and an aftermarket harness. Just make sure it includes knock sensors and the factory narrow band front O2 sensors.
BTW, I hear ya on the hassles of running nines.
Your project will will be fun and run well!
Ron
Got ya on VVT. We did a lot with that in the Dodges. I don’t know doodly squat on the GM stuff.
Might be best to get a PCM and an aftermarket harness. Just make sure it includes knock sensors and the factory narrow band front O2 sensors.
BTW, I hear ya on the hassles of running nines.
Your project will will be fun and run well!
Ron
I still have shock towers too, at this point I'm too deep into the CBR frontend to clip it even though I know my hands would be so much happier if I did, but hey maybe with a LSx I won't need to mess with it as much.
10-09-2020, 06:35 PM
#17
Thanks. We like Novas.
Mine is also foot brake, CalTracs, 275 pro drag radials. I’ve no trailer.....
I’m 65, the damn thing scares me.
next year with more seat time, will be better. Been a weird year.
Yours sounds well sorted! Love the first gens.
Enjoy man
Mine is also foot brake, CalTracs, 275 pro drag radials. I’ve no trailer.....
I’m 65, the damn thing scares me.
next year with more seat time, will be better. Been a weird year.
Yours sounds well sorted! Love the first gens.
Enjoy man