The plates are aluminum and the steel epoxy is whatever. May have a problem with expansion from heating a cooling at different rates, which could eventually allow one of those putty plugs to come out and toast the engine.
Might be a great cheap solution, but I wouldn't risk my engine to save a couple hundred bucks. Did you do your engine first or your buddies?
chevy runs deep, Don't step in chevy!
289 - Holley 4150 570cfm; Performer intake; mild cam; MSD HEI; 302 heads; Roller Tips; Hedman Tri-Y headers; H-pipe w/Flowmaster 40's; 9 in posi 3.50; 205/50-17F; 225/50-17R.