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Leaded gas-probably don't need the lead substitute-small carb?

You probably don't need the lead substitute.The vehicle must have been set up to run on leaded or unleaded.I'm sure it has the hardened valve seats that unleaded gas requires.There wouldn't be any point in building it without the hardened parts.Of course, if your owners manual says it needs a lead substitute.....I'm wrong.
If you have a pile of money you could put an aftermarket ELECTRONIC fuel injection on it; I think Edelbrock,and probably Holly make a system for it.This probably would increase your mpg,and maybe the performance.I think they are expensive-$1500 or so-so it really isn't practical.
Same story on trying to cobble together later GM FI and graft in on.
One cheap idea would be to find the smallest 4 barrel carb you can-used-and put it on.With small primaries it might improve throttle response and MPG a little.It will kill peak power,of course, but who uses peak power very often?
Luck,
Charlie
 

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Hardened seats-late 70's I think- Do you have high compression?

DJ Friction,
I'm pretty sure you got the hardened seats.It would have cost GM more to make it without hardened seats,so they wouldn't have any reason to use unhardened seats. I think they called the hardened alloy-"stellite"-or something like that. I had to look this up years ago because I had a bunch of late 70's motorcycles,and they were leaded gas motors, but could use unleaded because the japanese had switched over by the late 70's.
L
Hey, have you checked to see when GM offered those monsters with TBI? My understanding is that the TBI is much less computer controlled than the later FI.They-the TBI were designed to fit non FI motors,so a TBI and its manifold might bolt on..You might get away with just a mass air sensor in the airbox snorkle,and maybe a O2 sensor in the exhaust. They would send a signal to the Electronic control,it sends a signal to the TBI.
Might be fun to try, but $$ wise-even with junkyard prices-you could never make the $ back in saved gas.
Thanks,
Charlie
PS I wonder if you got a higher compression motor also?
I bet the real reason behind the "leaded gas" was to save the price of the cat con-they were expensive back then.GM and the commercial buyers/farmers might have convinced the EPA that they needed occasional leaded gas to lube the valve stems or rings in hard commercial use.It was probably BS,and a way to make cheaper vehicles with lower maintenance costs. Leaded gas did kill spark plugs kinda early-3000-5000 miles-, but they are cheap.
 
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