C4 Weak Points

[John Grunwald]

Just about to FINALLY build up my C4
Its going into a 69 coupe, behind a 331 making around 400ish hp, this car isn't a dedicated drag/race car, just something i'll be bringing out to the 1/8th and maybe some autocross events.
I'm going to be using broader performance's 500hp kit with a full manual reverse and ratchet shifter.
Are the hardened input shafts really necessary? It will probably see a 100 shot spray at some point once i get the suspension set up right. And is there anything else i should change while i have it out? It also has a 3200 tci street fighter converter.
I was also debating on changing it to a gforce t5, and make it handle a little better to try to get into road racing. Does anyone have any experience with them? And are they ok for street use?
Thanks!

 

[rbohm]

so you are looking to put 500hp through a C4, not an issue. start with a good rebuild using top quality parts. add to that a good shift kit to firm up the shifts, and you will have a C4 that can handle the power and still work nicely on the street.

 

[horse sence]

C4 are very tough when built right .i have one that was behind my 351 W. it puts out just over 500 hp .we used them in the off road race truck and the only problem was the bell housing cracking from taking hard jarring jumps.