so i got a 78 with a 400 and C6, just wondering what peoples redlines are? motor is a rebuild with no really mods. when i floor the sucker and it starts moving motor goes up to about 4500-5000 and i swear it sounds liek its gonna jsut blow everthing to **** so i lay off and let it shift ( too scared to see what actually happens ) so what do your guys' trucks go to?

 

Id say 5 grand is the absolute max for a stock 400. But I would play it safe and definatly keep it below 4500.

 

yeah id say about 4300-4500 would be as high as id rev it,

common sense dictates if it sounds like shes gonna explode dont rev that high

 

i revved my 351m to over 5k, and ive done it a bunch... stock with 151k miles. still no knocks or anything..

 

Normally I would expect the automatic to upshift before 5000 RPM by itself... even at WOT. I wonder if the transmission needs some adjustment or maintenance.

 

yeah idont think i'll go past 5 but i was just curious, while it does sound liek it could be bad it also sounds really cool haha, thanks for your input guys

 

tranny feels really good not 100% sure but i think it was redone before i bought the truck.

 

If you floor it your in the kickdown circuit which bypasses the modulator, and works strictly off of Governor pressure. As sticking governor can cause one to stick in gear, but that may not be the case, there are a lot of variables in an Autotranny. At any rate I don't see it being a big deal, I might adjust the kickdown lever a bit so that it comes in a little later, and drive the crap out of it.

 

4600-4700 sounds about like where my C-6 shifts, it's likely been 15-20 years since I held it WOT though ....

 

i try to avoid the "driving the crap out of it" due to the cost of gasoline haha, but cant help but giv'n it all i can once in a while.