4L60E vs TH400
Thread Starter
Teching In
Joined: Sep 2019
Posts: 21
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Yes. The early ls1 4th gen flexplates have the correct holes already drilled for the sbc/bbc converter lug pattern. The later flexplates and some of the sfi plates for our cars like the B&M one for example, do not. You have to drill them yourself. If you are not high HP, just grab one of these.. I have done over 50k miles at 540fwhp with this style flexplate behind a th400 in the past. This style below are also stronger than the later style (which rather than round holes the later ones have bigger oblong holes cut out in them)
https://www.ebay.com/itm/98-02-LS1-V...sAAOSwO0VeEL9e
https://www.ebay.com/itm/98-02-LS1-V...sAAOSwO0VeEL9e
So, I need that adapter ring and move the bolt holes, correct?
11 Second Club
Joined: Jan 2003
Posts: 1,000
Likes: 134
Yes that is the later flexplate which will work with the adapter ring. With the converter holes you have to check them before fitting the trans. Flip the converter over on it's snout and put the flexplate over it as it would be bolted up in the car. Depending which converter you have there are differences. With that plate you will probably have to drill new holes for the converter.
Thread Starter
Teching In
Joined: Sep 2019
Posts: 21
Likes: 0
Yes that is the later flexplate which will work with the adapter ring. With the converter holes you have to check them before fitting the trans. Flip the converter over on it's snout and put the flexplate over it as it would be bolted up in the car. Depending which converter you have there are differences. With that plate you will probably have to drill new holes for the converter.
Hi,
what gearbox would be the best choice for an lm7 with summit stage 3 truck cam and 243 heads? Its going in to an impala 65. What do I need to do to get the th400 on there? This adapter ring and nothing more? Thanks.
BTW, do I need a high stall converter? Im not gonna race it.
what gearbox would be the best choice for an lm7 with summit stage 3 truck cam and 243 heads? Its going in to an impala 65. What do I need to do to get the th400 on there? This adapter ring and nothing more? Thanks.
BTW, do I need a high stall converter? Im not gonna race it.
You mentioned the 400 so some of the parts needed for that swap: crossmember(we sell BMR), cooler, crank adapter(or custom converter for dished flexplate).
The transmission will bolt up no issues you just won't use the 12'oclock bolt hole.
If you plan to race it, especially more than street driving, then i would definitely go with a higher stall converter, if you are street driving it you can still do a more modest stall converter that will offer a balance of both.
__________________
FTI COMPETITION CONVERTERS AND TRANSMISSIONS
"IT'S NOT CHEATING, IT'S THE COMPETITIVE EDGE."
1-866-726-8358
info@ftiperformance.com
FTIPerformance.com
FTI Converter build sheet
FTI COMPETITION CONVERTERS AND TRANSMISSIONS
"IT'S NOT CHEATING, IT'S THE COMPETITIVE EDGE."
1-866-726-8358
info@ftiperformance.com
FTIPerformance.com
FTI Converter build sheet
