[My427stang]

Motor mounts are the same for all FE's and are broken down into early and late. Early models used a 2 bolt boss on the block and late used a 3 bolt setup. I do not believe there were any 2 bolt 428's.

As far as 428 on the inside water jacket, I have seen plenty that didnt have that, although its worth looking if you can get at a freeze plug.

Bottom line though, a 390 built to the same specs as a 428 will be pretty darn close in performance. Some things to think about:

390's and 428's love CJ size valves (2.09 / 1.67) and if you go to a steeped shank valve (I like Ferrea) you'll get some added low lift flow. In addition the bigger valves get to some new metal for the valve seats

Dont be afraid to cam it, its not a small block Chevy, anything under 280 duration isnt enough. I run a 280H Comp Cams in a pickup and it has more low end than you can shake a stick at in a 4x4 pickup. In a lighter vehicle I'd run a 288 or 292 duration cam, it'll sound rowdy as hell, pull like mad, and you'll have plenty of low end

Get rid of that intake as your first improvement, thats a 390GT intake and they are good for nothing. My opinion, this is what I'd use in this order, and its all based on which I could get cheaper they are all very similar.

Edelbrock RPM (Best intake but most $$$)
Edelbrock F427 (Old style, much like a 428 PI)
Ford 428 PI alum (Great intake but $$$$)
Blue Thunder dual plane
428 CJ cast iron (great intake but HEAVY)

Stay away from a regular Performer, even if it was free, I lost performance through the entire curve on EVERY motor I tried them on, I eventually gave up trying them. Even the stock iron like you have does better. The RPM makes as much low end and comes alive around 2500