2dadoorz
+1y
I had a 91 with a 350 tbi in it. It was very under powered stock. I did some upgrades to it and It was ok after that. (exhaust, cam, intake, chip, ect) It was about 14 mpg average and 10 towing so not much better than my 454 tbi for mileage which gets about 10 no matter what I throw at it. Duallys are heavy so gas mileage always sucks. The tune port probably will work good. Just might want to check the specs on the cam to see where it builds the most power. High or low rpms. Check out this article I might try something like this but make it the 383 stroker for a 95 I am driving now.