[Bronco]

I have a 351 Modified in my bronco right now I was wanting to take the 400 out of my 77 f250 because it runs better and has a lot more power anyone know if I am in for a headache? I know the 351m and 400 is practicallly the same but was told the oilpan and heads might cause a problem for me. The bronco has a c-6 tranny which If I am not mistaken will bolt right up. If anyone can help me I would appreciate it.

 

[stepside454]

the heads are the same on the 351-M & 400...same as 2 barrel 351C also. not sure about the oil pans. I think they innerchange. Id go for the 400 personally

 

[Bronco]

just hopeing I havce aenough room to put the 400 in with the headers it has on it they hug the motor but passanger side of 81 bronco does have a lot of room

 

[swvalcon]

IF your 351m will fit so will the 400. No difference in external size of block. Everything that makes a 351m or 400 is internal. You can take a 351m and make it a 400 just by changing crank, rods and pistons or vice a versa.

 

[Bronco]

Thanks for the info I will let everyone know how the swap turns out. That 400 is much faster than the 351m not sure what the vehicle wieght difference is between 77 f-250 and 81 bronco but I am hoping to see a large increase in performance.

 

[xntrik]

Long tube headers really help a stock 400. Installing a '71 timing gear helps a lot also. The later model engines have the cam timing retarded. You probably need a new timing set anyway due to stretch.

Ford Guy