0331 to 0630 head adapter plate (Any issues?)

I see a lot of people on the forum have swapped the cracked 0331 head for an 0630 head. Wilsmick has the adapter plate to reduce the exhaust ports to allow the stock exhaust manifold to bolt up. I am looking for some feedback from those who have done it now that some time has passed.

Please provide mileage since, average MPG changes, change in power, other issues, etc.

It seems like it would affect performance some due to buildup next to the plate on the head side and reduced overall exhaust flow without a smooth transition into the manifold. I am looking to do this on a CA emission 2001 so my options for using an earlier year manifold are not there. Thanks for any feedback.

bump

Easiest solution is to spend $370-400 for the new improved thicker casting 0331(will specify this in ad) with reman'd valvetrain, but new seals and 2+ year warranty(they'll want your old head as a core so they can throw the good parts of your valvetrain on the next new cast head they build). If you do chance upon a cheaper used 0331 head, make sure it's off a 2002+ jeep. Another solution is to use the older 7120 or 0630 heads and use aftermarket or replacement headers(most stock jy ones are cracked/not worth it). Keep in mind how many o2 sensors your jeep has and how many bungs are available in the different model headers. Using an adapter plate would be my last option.

free bump, might be doing this soon