That about sums it up. “It was the best we had”. And that’s not saying much. Bolt-ons produce little to no gains and it actually loses power with H/C “upgrades”. Who would have ever predicted that could happen on a SOHC cast iron engine designed to power an E-Series.
You were “turning heads everywhere” because of the obnoxious noise coming from your truck. Most people probably thought the exhaust fell off a UPS truck. Joke was on them when they didn’t get their package. Instead, it was you parading around thinking your truck actually sounds good. The 6.2 was never intended to be used in a performance application, period. That is why it has such bad noise characteristics with any aftermarket exhaust; the rasp and drone are terrible.
As far as the 3.5, the cab does not need to be, nor should be, removed to replace VCT sprockets. So maybe try absorbing some information instead of constantly spouting off about things you don’t understand.