How about a Massey Fergeson 4cyl like used in the British sports cars ( MG, Triumph Spitfire ect... ). mod to use a Holley 2300 2bbl, J pipe a turbocharger in, but use a cable operated exhaust cutout before turbo, then pipe the cutout side back into the exhaust, so you could open up the cutout, to act as a bypass, so when you wanted no turbo, you didn't need it, just pull a . they still got pretty decent MPG numbers. run 5-8 psi, you would still have a fun little car, when u wanted, and it would have a neat motor. 80's-90's Volvo 4cyl station wagons often had turbo's, there small and would work perfectly for what you would want. 2" hose outlets, 2" hose inlets, smaller Garrets is what they are. check for shaft end play, and make shure no oil is in intake side, if so, it's an oil burner. I could have had a couple for $40 each at the junkyard, but they were 2 small for my 6. there bolted directly to the exhaust manifold from the inside so you have to remove manifold to remove turbo, bolts are easy to get to. volvo motors are 2.4's