I've finished my 351 and have it sitting in an old bunky fairlane at the mo just to get it all tuned in and make sure theres no leaks before it goes in the XB.Currently the engine stands as a 351C 4V closed heads, roller rockers ,weiand accel manifold,Crane Digital Ignition system,Mild cam 2500-6000,and a 750 Vac sec Holley Street Avenger.Question is and I think I might be talking about Chalk and Cheese here ,but ,would it be worth investing in a Barry Grant Demon 750(Mighty,Road???).I know price wise is a big difference but when we dyno'ed the engine it seemed the holley was starting to suffer at hi revs.I've had the carb tuned and jetted correctly (so I'm told) but still got probs.One more reason is this is the second street avenger I've had on it,1st one had vac leaks through butterfly bushes(brand new).Idea's people???????Ta