Just remember to have your facts straight and
backed up before you head down there to "set them straight". The last thing you want to do is to look like an idiot and have your friend look worse.
If your friend build and engine for this guy and he is low enough not to give the correct credit, he may be low enough to try other things.
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White 1995 Mustang GT
Dynomax Cat-Back, Offroad H-pipe, K&N Filters w/o Air Silencer
My 1995 Mustang GT