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That's odd, the LQ9 did not have a long crank variant only the LQ4s did, did you use a 4l80 or swap flex plate? If you didn't it would be darn near impossible to properly register the converter into the pump without a massive amount of shims.
I used the stock LQ9 flexplate, no adapter was required. I just drilled new holes for the converter to bolt up. Just one bolt is missing on the case, but other than that it works.
So I might go down for this if anyone wants a hand. When they do these sales that usually includes all belt driven accessories. You would probably have to pay for a harness and PCM if you needed one. So it might be $250 out the door if you needed that stuff too.
I used the stock LQ9 flexplate, no adapter was required. I just drilled new holes for the converter to bolt up. Just one bolt is missing on the case, but other than that it works.
Ahh, the drilling is a new one, im not a fan of the drilling or wallowing holes though, it works, but unscheduled rapid dissambely of a flex-plate is never a pretty sight. IMO, the couple hundred bucks for a flex plate beats losing a leg or worse.
Ahh, the drilling is a new one, im not a fan of the drilling or wallowing holes though, it works, but unscheduled rapid dissambely of a flex-plate is never a pretty sight. IMO, the couple hundred bucks for a flex plate beats losing a leg or worse.
Hah funny, my car is a stock 85 vette, stock fuel pump, stock radiator, stock transmission, stock dana 36. Its has 15000 miles on my LS swap. My kid drive the car these days. The motor will be out in a few weeks, so I will post pictures of the flex plate. I bet that its still 100% as the day it went it.
Hah still getting its not going to work. Buddy, you made my day
Hah funny, my car is a stock 85 vette, stock fuel pump, stock radiator, stock transmission, stock dana 36. Its has 15000 miles on my LS swap. My kid drive the car these days. The motor will be out in a few weeks, so I will post pictures of the flex plate. I bet that its still 100% as the day it went it.
Hah still getting its not going to work. Buddy, you made my day
Never said it wouldn't work, it does but it isn't without issues.
My 03 truck with 210k at the time making all of the stock 285HP on a good day, broke the flexplate around all the retaining bolts and had 2 cracks from the center all the way through the ring gear, stock flex plate and trans mind you. Sounded like lifters at first, then rod knock and then got hollower and louder, on a C4 with how relatively difficult it is to pull the trans, IMO a multi-pattern flexplate is the safer and cheaper bet.
Take a look at any multi-pattern flex plate and you'll notice a few things, they're either solid with very little mass reduction with thick mounting pads to mimic the dish or a small dish, or have added material around each of the converter mounting locations with mass reducing slots and holes.
In a cammed LS swap spinning at let's say 7k, the centrifugal forces are immense, while a stock flex plate could have handled that fine, one with extended or new bolt holes definelty cannot with the same reliability and safety factor as that is way outside of the intended use case and design parameters.
Last edited by ThatOneKid; Jun 9, 2021 at 10:56 AM.
I'll be honest I've done a lot of backwoods redneck engineering on my LS swapped 84 and I don't think I would drill a flex plate. I don't see an issue with it necessarily. But it seems like a lot of work to get it lined up properly. Especially when LS flex plates are so prolific in the junk yard. I have 4 different versions of LS flex plates in my garage right now. Some flat some dished. Some with a spacer. That and if you go with FTI for your converter they send an adapter with it so you can use any factory flex plate. Or you can order a converter with whatever bolt pattern you need.
Here is a picture of the flex plate. Most flex plates fail at the hub, not at the converter bolts. I agree that the sfi flex plate is the best (I had order two different TCI plates and none fit) fix but for really that is more for guys that use trans brakes, 5000 stall converters and 12in slicks/4.88 gears.
Not sure why chevy just uses three bolts, dodge uses six high grade bolts. I had a few flex plate failures on diesel pick-up, you can hear them when there failed. Worst case is you get the hub break from the outside of the plate.
Last edited by Mike Holmen; Jun 14, 2021 at 10:08 AM.
Here is a picture of the flex plate. Most flex plates fail at the hub, not at the converter bolts. I agree that the sfi flex plate is the best (I had order two different TCI plates and none fit) fix but for really that is more for guys that use trans brakes, 5000 stall converters and 12in slicks/4.88 gears.
Not sure why chevy just uses three bolts, dodge uses six high grade bolts. I had a few flex plate failures on diesel pick-up, you can hear them when there failed. Worst case is you get the hub break from the outside of the plate.
Most stock converters fail at the hub, the same cannot be said for modified ones, it's just as common for them to crack, usually starting at a bolt whole and working its way out, and if they're failing at stock power levels with no modifications, one can only imagine how a modified one will fail at the 1.5x power jump that just a cam and a tune will get you on an LS.
Only the 60e family uses three bolts since it is a light duty transmission, the 80e family uses six. You can get 80e style flexplate and TC for a 60e but it's a huge expense unless you can prove that you're making enough power to shear or flex the bolts to where it's a problem.
Last edited by ThatOneKid; Jun 15, 2021 at 01:22 AM.
