I’m looking at B&C backup alternators and there are a couple of options available. The unknown is how much space is available between the vacuum pump pad where the alternator will be installed and the firewall. TJ from B&C wasn’t completely sure that the larger of the two would fit. I believe he said 8 inches was needed. Does anybody know this measurement off hand or can they measure it if their cowling is off? It would be much appreciated!!