X heads on a 360?

The problem with your logic is, he already has 2.02's in the X head and doesn't have to spend a dime to upgrade the other heads which are inferior at present. Not all heads port out the same. While the early castings can be ported well, I have not seen them go as well as the XJOU.... heads. I know that doesn't mean someone can do that work......

The 2.02 can indeed make 20+ HP over a 1.88. No question. Seen more power differences between the two. HOWEVER! It is also the combo tested that shows a big or small one. Even mild builds have a good spread.

At this point, I can't see selling the X head to roll the sale cash into a smog head that starts with getting rid of 1.88 in favor of a 2.02. IMO, that is just insanity.

The "bear in the room" is the type of porting that was done.
Everyone says that you can't port them head to big with out finding water.
Well my first porting job i DID. On a 340. No power until 3500-4000 rpm, then ran grate. On a street car these heads SUCKED!
Wish i still had these head, now that i have a 4200 stall in 408......I may have like them a lot!!!!!
If they are ported like my first set, in somewhat of a street car set up. They won't be on there for long.
But the only way to know is to bolt them on. and then go the back up route later if needed.

Remember, 50 to 60% of the port flow can be improved with a simple, but good 3 to 4 angle valve job.
Soooo if the 1.88 had a "standard" valve and seat cut and the 2.02 had a good 3 angle valve seat cut, with a little blending..........You bet your bottom dollar it will make 20+ HP gain.

As i said before, Try the X head, you my like it.......and if you don't.....your only out the gasket set. And it is a X head, that is re sellable because it its the X head.