Big block help

[brad20653]

I have a 400 in my 68 want a 454 what all is needed for the change from the shroud to whatever make me a list Thanks

[lukecp]

Assuming you have a 400 small block and not a big block, the change shouldn't be very hard. You need the correct big-block motor mounts, as well as the big-block alternator brackets, as well as PS and AC brackets if you have either of those accessories. I dont know if the fan shroud is different or not.

What i would try to do is find a complete, running 454 and drop it in your truck, and use 67-72 BB motor mounts, and it should be a pretty easy conversion

[miket]

Brad,

You may have a 400 badged truck which is actually a 402 big block...if so...you shouldn't have to change anything unless it's old and in need of update.

You should be able to tell for sure by looking at the valve covers...they are much larger than a small block. You can also tell by pulling the numbers off the block (rear ledge behind valve covers) and go to www.mortec.com....look it up there.

However if you do have a 400 small block then you will need all the small block to big block conversion parts. Take a look at my site...I put a small list of things required when I did my retrofit to the 502.

Hope that helps.