Guido, what year is that Avanti? My Great Uncle in North CA has a '76 Avanti II that he and My Great Aunt bought new from the factory that has a Pontiac 400 between the frame rails. He also has a fully restored '57 Golden Hawk with the 289 and factory Supercharger (I think the supercharger was made by either Paxton or McCulloch).
Here's one of mine:
The front has been fixed now. I bought it that way as the previous owner used it as his service truck fr combines, swathers and tractors and he had backed a combine into it...
2002 F-350 Chassis Cab - 7.3/ZF-6, Manual T-case 4x4 with 450 rear springs. I put stage 1.5 injectors, a wicked wheel II inducer wheel, TS-6 position switch, straight piped factory exhaust, gauges for fuel, EGT and boost, did the 6637 filter mod and new glow plugs. The only things it needs to be mechanically perfect are new rear axle seal and a rear pinion seal, T-case rebuilt and new front springs and shocks installed. I'm going to do the rear-end and see if I can sell it for 13K. If not, then I'll fix the T-case and do some interior tweaks and keep it. 220K on the clock and gets 14 all around empty and 10-12 towing. It could get better mileage if it didn't have 4:10 gears, but it pulls VERY well. I have a possibility waiting in the wings which is why I'm debating selling it. Otherwise, if I keep it eventually I'll sell the 7.3 and put a 6.7 Cummins in it and call it a day.
Otherwise I have an '03 Beetle TDI as my work car (50 mile round trip every day and 42-46mpg is NICE), The wife has a '13 Passat TDI and we also have an '06 Toyota Sequoia.
My Dad's '03 F-250 reg cab 4x4 6.0PSD/5r110 usually lives at my place too and it is hell for stout now being bullet proofed. It pulls almost as well at slow speed as mine and out pulls it on the highway... If you kepp your foot out of it, you can get 17-18 with it empty.