I have a 67 conv.right now im running a 350. I have found a 406 pushing 450hp. I started asking around to make sure everything would run right. I have head of people having trouble with them over heating, and clearing the firewall. does anyone know any of that?

 

well is the block filled? That would case over heat. Then u could run an electric fan with an oversized rad.

as for the firewall make sure u use short valve covers.

should be good.

 

I am not sure if I remember this properly, but I seem to recall a thread similar to this whereit was mentioned that the A/C fan and stuff for it on the fire wall had to be removed to get a bigger mil to fit. I would think that would be the only issue with clearing the firewall.

 

some 400 small blocks run hot because of thin piston walls,i know they have the steam holes between the cylinders to help that...my 400 runs no more than 180 threw traffic here in florida and its pretty radical,i have dart heads on it too,so the steam holes mean nothing...i have a stock looking performance water pump,a beecool radiator and the plastic,not flex fan,but plastic fan and no electric fan...as far as fitting,its the same block as a 350 or 327,it shouldnt matter...i believe..
my 400 is the 3 freeze plug block too,the 2 freeze plug block was a better block and not many guys know they existed...i have one of those prepped and sitting on a stand....
Its true the 400s run hot sometimes,exspecially when bored too much,my block was a friends old block and it was just one of those set-ups that just worked great?he had it for years,and i wanted it...so i finnaly got it.....
just dont sinch on the radiator and fan and you should be fine and stay away from a 40 or more over block....