How hard would it be to grab the TBI unit off a suburban or blazer and adapt it for use on an early 70's Buick 350? The Buick already has a GM HEI dizzy on it, as well as a four barrel intake.

Things I'm thinking of are computer problems. Would I need to rig an oxygen sensor? Would the throttle body bolt up? Etc...

I know there are a bunch of aftermarket conversions out there that will work with GM small blocks, but they generally run $$$. Would I be able to accomplish this with salvage parts for cheap? Or am I suffering from a delusion?
This motor is going in an old jeep pickup with a TH400/Dana 20

Easy swap.

Weld in a bung for the O2 sensor. The Throttle body will not bolt on. Making an adapter is very easy though. If you don't have access to some machines, AFI will probably sell you an adapter plate. Other than that it's a piece of cake. You can chose the have the computer run your distributor, or you can run it stand alone. TBI came both ways. Computer controlled distibutor won't have a vacuum advance. The computer won't care if it's a Chevy or Buick motor.

If you get the right computer and matching harness you can have the chip reprogrammed to get the best tune for your engine.

Sounds like I'm on the right track. What should I look for when searching for a doner system? Blazer or suburban unit, correct? What years would be best?
Other than that I guess I'll be done for now. Just a matter of finding the parts, the swap won't be for a while yet. Thanks