Originally posted by lluciano77
The 5.7 rods aren't too important. They will only show minimal gains. I would recommend them only if you are starting from scratch.
A 400 should make 350hp easy with your cam.
If you went to 2.5" exhausts your engine would make even more power. 2 1/4" is small for a performance 400. It isn't like a 350. That extra 1/4" will make a big difference.
Of course, an aftermarket head will be needed if you want to get to the 400hp range easily.
I use the Percy's aluminum gaskets. They work well. I have even reused them and still had them seal.
My recommendation of 5.7 had nothing to do with power gains. It was to take some stress off of the pistons. He is at the limit of what the stock cast pistons with short rods can reliably take.