5k leaning out

[William M. Lockwood-III]

My 88 5ktq with the TAP chip and 3" exhaust is seeming a little
strange.  When I went from stock exhaust to the 3" exhaust my boost level
increased from 12.5 or so to 14.5 or 15.  The car seems to flatten out a
bit in the upper RPM now.  Around 5500 or so.  Is this the mixture leaning
out because of the extra (extra) boost?  Or is this the cam just being
weak at this RPM.  Or the exhaust manifold being only so good.  Etc?  I
just don't want to blow up my car in such a foolish way.  At least not
yet.

I run Sunoco 94 most of the time, but I planning on trying some "C12" (i
think) from a local speed shop, to  see what it does. And here in VT the
winter temps are generally good for serious horsepower.  Last year we had
a week at -17 F that was good.

Oh and I just remembered, my coolant level has gone down a little bit
since the increase boost.  Am I lifting the head off the block?  Or am I
going to be in trouble soon?

Bill