Also recomend sending the heads to a machine shop for cleaning/surfacing/pressure testing. But you can check for warpage with a straight edge and a feeler gauge and hope for the best. I believe 0.007 inch is the limit. This info comes from my 91 Cougar 3.8l but I'm pretty sure the block and heads are the same.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.