SBC 400 FLEXPLATE???'s

I've used Summit and pioneer.

Ive ran one once with a 350 flex plate was barly noticeable motor idle was simular to a v8 with a small cam just a little waver or simular to the slightest carb load up ...can't recomend but they have been dune that way...read article said someone drilled and filled there crank weights and claimed to use titanium studs threaded(pressed) into crank weights to decrease weight on the heavy side negating the external balance

I used the Summit one on my TH400/383. SFI 29.1 Blueprint motors approved. It’s actually the one I had on my TH350. 153 tooth. Been working great. No complaints.

SS_Malibu said:

I used the Summit one on my TH400/383. SFI 29.1 Blueprint motors approved. It’s actually the one I had on my TH350. 153 tooth. Been working great. No complaints.

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Isn’t your motor internally balanced? It f yes, then that won’t work for the OP - he needs external balance

64nailhead said:

Isn’t your motor internally balanced? It f yes, then that won’t work for the OP - he needs external balance

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Yes, the motor is internally balanced. The flex plate I have is externally balanced. I purchased one recommended by Blueprint.

Blueprint engines recommended an external balanced flywheel for an internal balanced 383?

64nailhead said:

Isn’t your motor internally balanced? It f yes, then that won’t work for the OP - he needs external balance

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1983calais said:

Blueprint engines recommended an external balanced flywheel for an internal balanced 383?

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I went back and looked. I had that wrong. Blueprint uses and weighted harmonic balancer and a weighted flex plate. What I do remember is I got what they recommended. An externally balanced flex plate for a one piece rear main seal.

Thank you guys.