If he wants a spare so he can at least drive his car I completely understand. I have never gone forward with buying and installing a Holley where I should have 25 years ago. This way I could have taken the QJet and worked on it until I got it right without the car sitting dead in the water. In 1985 I outfitted a 77 Chevelle with a Holley and it picked up a bunch of power and ran perfect right out of the box. For the time it was perfect and I never changed anything about the carb.
FWIW I have instead pursued finding additional OHC carbs which has landed me a pile of carb bodies, old unusable parts, a mountain of cleaning crap in the garage and no working spare carb. To date I have spent approximately $1000 dollars on all of this where I could have just bought a Holley for a couple hundred and made up some throttle brackets.
