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Discussion Starter · #1 ·
I have a 70 H code mach with an FMX Trany...I'm wondering if it will hold up when beef up the motor. Or should I find a C-6 to work with.
 

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When I had my 351C built I was told that my FMX would need to be built also. I can let know know what I had done to it tonight when I look at the invoice.

Mike
 

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What type of hp are we talking here? Unless you are planning on 500hp or more the FMX is just fine. If you are planning on more than 500hp a C-6 will need some work done to it as well. Both transmissions can handle quite a bit of punishment. The FMX is cast iron so it is heavier than a C-6, but I believe that the FMX robs less hp than a C-6...someone correct me if I'm wrong.
 

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My 71 mach1 is a 351 v4 c6.I also have a 72 fb 351c 2v with a fmx.Just driving around I cant tell a lot of difference.
 

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I believe the FMX is pretty durable it just doesn't have as much aftermarket stuff available for it(convertors,shift kits etc)...Both the FMX and C-6s are horsepower hogs compared to a C-4.
 

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I've known a few racers to run a C4 behind a 351. I have :) I know a stock one is good for at least 450HP, if built right. Likely more if some changes are made. I agree about the parasitic losses. Blueprinting and a few parts changes can make a big difference in those numbers as well.

Pat
 
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