In the late 60's my friend Leon dick ed up his 283" '57 Vette with a 301(maybe a little more) block and fuelie heads. The Powerglide car looked pure stock but was heavily breathed upon by some of the best in the Boston area. The block was tanked clean then assembled bare with no paint and we poured muriatic acid on it to let it age then we threw some accelerant on it and burned it to look even worse. We spent hours with grinders files and J-7 body filler reshaping the camel hump heads to look like old standard power pack heads. The final deal I did was to close up two holes on the valve covers with JB Weld then drill 2 new ones in the staggered position and poured a shit load of liquid gasket maker on the valve cover gaskets. It kinda sealed the engine up but it still weep-ed a little oil out of my disguised straight over holes. That was to be our undoing. On the starter line one Sunday the order came down to kill the engine because of oil flowing from the mill down onto the strips surface. The tech guy got real interested when he and the tree guy were studying the leaky valve covers and spotted my bogus modifications on the valve covers. Also his magnet did not stick too firmly to the front of the heads. When talk of "pumping" the engine came up we just quietly packed up and became spectators for the final weeks of the season. We really weren't big deal racers but we thought we were cool anyhow.