LSX with 4+3?
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
LSX with 4+3?
Has anyone done an lsx swap in a C4 but used the 4+3 tranny?
Ive been gathering parts to swap into my thirdgen but I'm much rather swap my '88. I already have the 621 big block bellhousing as well as ls1 intake and f-body oil pan. Using the factory 4+3 would take care of the c-beam adapter issue. Also I was thinking a hydraulic TOB would have to be used since the 621 doesn't have the mount for the slave cyl.
Ive been gathering parts to swap into my thirdgen but I'm much rather swap my '88. I already have the 621 big block bellhousing as well as ls1 intake and f-body oil pan. Using the factory 4+3 would take care of the c-beam adapter issue. Also I was thinking a hydraulic TOB would have to be used since the 621 doesn't have the mount for the slave cyl.
Last edited by armybyrd; Dec 14, 2016 at 04:09 PM.
Racer
Joined: Jul 2015
Posts: 313
Likes: 15
From: Modesto Ca
The 4+3 is just a Borg super t10 with an od on the back.There is a guy in a youtube vid that explains how to do this.I think the formula was a 4.8 pick up flywheel+ 2004-2006 gto pilot bearing + the correct spline count clutch disc.The pilot bearing was not driven completely in.The vid was done a tri5 chevy with ls motor+ super t10 trans.The part the has me wondering is that faxt that the standard sbc bell housing will bolt to the ls motor but you can only use 5 bell housing bolts.with the c4 not using a crossmember to hold up the rear of the trans I would be afraid of cracking a bell housing.On the modern lsx motors the bell housing to engine uses more bolts than the standard sbc .The bell housing also bolts to the oil pan.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
well now I've got a few more months to decide which route to go since someone pulled out in front of me last night and I totaled the truck. Have a broken knee so it'll prob be awhile til I can drive a manual again.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
although this is true it would still be a slow L98 even after a 6 speed swap. I've got most of the parts needed for the lsx swap-just need a wastegate, bov hydraulic tob and maybe one of two other parts. My 4+3 has never given me any issues in the ten years I've owned the car. Plus I figured it would make things easier not having to come up with a c-beam mount/adapter.
Last edited by armybyrd; Dec 17, 2016 at 09:11 PM.
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Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
I bought a C-beam adapter as it was cheaper than buying a wire feed welder, but it wouldn't be hard to fab up. The LSx swap with forced induction will make a T56 swap look like a cake walk. It is your car, follow your muse. There is certainly room here for the combo you are thinking of. I hope your injury heals up quick.
where did you buy an adapter?
I appreciate the sympathy from my accident-getting knee surgery Tuesday and decided to get a lawyer also since it wasn't my fault.
In the meantime reading about car stuff will be about all I can do. :/
Last edited by armybyrd; Dec 18, 2016 at 05:39 PM.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
i heard he used to make them awhile back and filled out one of the info requests on his website but never got a reply. How much did the adapter cost?
Last edited by armybyrd; Dec 19, 2016 at 04:54 AM.
Burning Brakes
Joined: Jun 2005
Posts: 1,188
Likes: 13
From: Wallingford Vermont
I have to agree with most everything said here. I've replaced my 4+3 with a T56, and still slogging the L98. I wouldn't even entertain the thought of a stock LS with the 4+3. It shouldn't be too hard to source an engine/trans combo. Search this forum and you'll see pictures of the Tommy Speed adapter and a few others. Talk to a welder/fabricator and it shouldn't be that hard to reverse-engineer what's needed.
And if you're serious about going turbo you might even want to consider a 4L80E.
And if you're serious about going turbo you might even want to consider a 4L80E.
Oil Producer
Joined: Apr 2014
Posts: 9,365
Likes: 2,734
well ive been follwing the comments here. i was going to swap in an lq9 and keep the 4+3. i read they were good for up to 375 hp which is more than ill make.
so guys is it truly a grenade issue or is it a keeping the rpm in the powerband issue?
like im doing a budget (as much as they can be) and this is why i was going to keep the 4+3.
Not only that, i was going to hpde it and just never use the od during that. its the 86 where i can turn off the od with a simple push of the button.
so guys is it truly a grenade issue or is it a keeping the rpm in the powerband issue?
like im doing a budget (as much as they can be) and this is why i was going to keep the 4+3.
Not only that, i was going to hpde it and just never use the od during that. its the 86 where i can turn off the od with a simple push of the button.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,454
Likes: 15
From: Martinsburg WV
There seems to be some confusion. When I made this thread I was asking about what was needed to make the tranny work. I could care less about everyone's personal opinions on the tranny. Same responses one would get when inquiring about anything to do with a t5 which I have behind a vortec 350 that's doing just fine.
Anytime I get into something I like to do my research online which a buddy always gives me crap for since it would seem a lot of forum guys reiterate what they've heard online with no firsthand knowledge or no fab skills. Now I'm not saying everyone but def a good share online. A buddy of mine has a t5 behind a 5.3 that's holding up just fine fwiw.
anyways i think I'll be able to figure the setup out-I've got a 621 bellhousing, lsx flywheel and I was counting on a hydraulic tob and my current 4+3 clutch. That leaves the starter.
Anytime I get into something I like to do my research online which a buddy always gives me crap for since it would seem a lot of forum guys reiterate what they've heard online with no firsthand knowledge or no fab skills. Now I'm not saying everyone but def a good share online. A buddy of mine has a t5 behind a 5.3 that's holding up just fine fwiw.
anyways i think I'll be able to figure the setup out-I've got a 621 bellhousing, lsx flywheel and I was counting on a hydraulic tob and my current 4+3 clutch. That leaves the starter.
Last edited by armybyrd; Dec 20, 2016 at 01:40 PM.
Oil Producer
Joined: Apr 2014
Posts: 9,365
Likes: 2,734
There seems to be some confusion. When I made this thread I was asking about what was needed to make the tranny work. I could care less about everyone's personal opinions on the tranny. Same responses one would get when inquiring about anything to do with a t5 which I have behind a vortec 350 that's doing just fine.
Anytime I get into something I like to do my research online which a buddy always gives me crap for since it would seem a lot of forum guys reiterate what they've heard online with no firsthand knowledge or no fab skills. Now I'm not saying everyone but def a good share online. A buddy of mine has a t5 behind a 5.3 that's holding up just fine fwiw.
anyways i think I'll be able to figure the setup out-I've got a 621 bellhousing, lsx flywheel and I was counting on a hydraulic tob and my current 4+3 clutch. That leaves the starter.
Anytime I get into something I like to do my research online which a buddy always gives me crap for since it would seem a lot of forum guys reiterate what they've heard online with no firsthand knowledge or no fab skills. Now I'm not saying everyone but def a good share online. A buddy of mine has a t5 behind a 5.3 that's holding up just fine fwiw.
anyways i think I'll be able to figure the setup out-I've got a 621 bellhousing, lsx flywheel and I was counting on a hydraulic tob and my current 4+3 clutch. That leaves the starter.
bazinga!!