I am coverting my 6spd. to a th400 and need to know which flexplate to get. I did a search and came up with a Jegs #60153 and a B&M #130-20238. When I had my engine balanced during the rebuild it was balanced to the factory flywheel and then I had the street twin clutch balanced to match my stock flywheel and everything worked great. I am afraid of getting the wrong flexplate for my combo. If I get either of the flexplates above do I have to have them balanced to match my street twin clutch? Do I have to grind the weight off of the flexplate? Thanks for any info.
Matt

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96 Camaro Z28 6spd., custom viper red with pearlcoat paintjob, 355 LT1 11.5-1, GTP stage 2 LT4 heads/intake, GTP-6 cam, full cage, moser 9" with 4.11's, and full suspension. Best so far after shakedown runs (hit rev limiter in the top of 3rd)...still needs tuning and suspension tweaking.
1.658 60', 11.886@116.05, 7.593@91.33 1/8 mile
Best mph 117.31
The Z under construction
92 Talon TSI 5spd. AWD Best E.T.-13.753@98.30mph
1.885 60ft.@13lbs boost--- For Sale!

 

The transmission doesn't care what flexplate is on the engine. If you had a 400 SBC then you need an externally balanced flexplate as well as the balancer. All you need is a flexplate that has the proper bolt patter for the torque converter you plan on using.

The reason they list different flexplates for TH400 and TH350 is because of the bolt pattern. A TH400 torque converter has a different bolt pattern on the flexplate. The TH400 and TH350 torque converters are interchangable so you can use both on each transmission and most good aftermarket flexplates have both bolt patterns on them.

The B&M flexplate you listed is for a 400 SBC. The Jegs flexplate is also listed for externally balanced but for newer model cars. The best thing to do is just call Jegs and ask them. Explain the conversion that you've done and they'll pick the proper flexplate that you need.

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87 IROC SuperPro race car
461 big block
Best ET on a time slip: 11.099
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Member of the Calgary Drag Racing Association

 

I used the B&M 20238 flexplate. It's exactly like the factory flexplate except it's SFI approved.

Good luck!

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...Brady
Twin Turbo 1996 Z28
Sponsored by YearOne
'98 B4C Camaro <--- FOR SALE

 

thats what i bought for my install also.......

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94 Z28 a4 soon to be a3, cowl hood,welds,9 inch,BMR trac pac,4" mufflex, Hooker LT's,2 stage NX wet kit,11.6 at 116 with a 1.56 60'<solid roller 383 with afr 210's still in the works>
Rich'sZ

 

Thanks for the replies! I am pretty sure that the B&M and the jegs part #'s I listed above are the ones that I need for the swap. I had the street twin clutch balanced to my stock flywheel so I did not have the engine internally balanced.
Matt