Engine Swap? What would I need?

[renny]

I currently have a 1985 4x4 K5 Blazer with atired 305 small block and a 700r4 tranny. What would I need to swap a 400 SBC from a 1977 Blazer with a TH350 into my truck? I only want to swap the engine. Are the flexplates different? would it be a straight bolt on to my tranny?
Thanks in advance for the help.

 

[big83chevy4x4]

the flexplates are different only that the 400 has a wieght and the 305 does not. do not use the 305 flexplate on the 400, it will kill the motor. but they will bolt straight up to your tranny.

 

[GRAYTEXK5]

you're probably going to anyway, but just in case...make sure you use the harmonic balancer for the 400 too.