Need better gas mileage and performance

[Dingman]

87 3/4 ton 2wd 454 TBI th400 LWB.

I know LMC sales a TBI that is bigger and, But, damn near $800 bucks......Not

Will the TBI spacer help that much?

I wish I could put a full Exhaust on it without violating the Fed regulations.

Should have purchased a older truck I guess, but I love this truck. Brings back the memories from younger years.

Anything else we can do to these engines without too much cost and legally?

Been reading about all the performance add-ons, just don't know what is the best bang for the buck.

Later