Anybody swapped in an LS1?

[Russell]

Yeah, that can be really frustrating, throwing parts at an EFI system in an attempt to fix a problem that can be caused by something seemingly completely un-related. Best way to service those rigs is to take it to the stealership, where they can use the factory service manual's troubleshooting guide to build up a list of suspect systems, and how to test them without simply replacing them.

The biggest thing to keep in mind is that it costs money to switch engines around all the time -- Is the money you spend on converting to diesel well spent? Diesel isn't that much cheaper, at least up here (99 cents a litre vs 1.17 for 87 octane), and I'd imagine it'd take a long time for the swap to pay itself off in fuel savings. You can buy a fair bit of gasoline for the 1500 or so you'd need to count on spending to install a 6.2L (including buying one) then turboing it.

And as far as the TH350 goes, it isn't possible to install one of them behind a diesel. Those transmissions need a vaccum signal to shift correctly, which can be solved with a special variable vaccum valve installed on the 6.2L / TH400 Military trucks, but, there is no such thing as a diesel TH350 torque converter or govenor, as far as I am aware.

Best bet is to run a standard, those diesels, even turbocharged, don't like being revved much past 2800 - 3000 rpm, and an auto simply has too much parasitic drag to work nicely.

SM465s are bolt ups to 6.2 and 6.5L diesels, and are 3 speed transmissions. You'd either need big tires, or very tall gears to keep your revs around 1800 - 1900 at 100 km/h for getting the best mileage, but that also means it is a real slug off the line. 700r4s, or NV4500 5 speed standards are a much better choice, since they have an overdrive gear, which lets you run a lower gear ratio to get up and go a bit better, but still get good highway mileage