vacume line is on the correct port for the ford dist. unhook and plug the line when setting the timing- for a 1971 4* btc is listed, 10* for most other years---starting around mid 70s they retarted the camshaft 8* and advancing it back up will help--when they lowered the compression and did all the smog stuff the econ went to hell but advancing the cam, more timing and possibly going to 68 - 70 jets in the primaries will help performance---It isn't a 4 wheel drive is it???