Does anybody know how fast a 1972 Gran torino sport should be able to go. I just bought one and there was a bunch of problems with the vacuum lines, timing and i tuned up a lot of other stuff. It was only hittin 70 before the engine would cut out. Now its up to 100 but thats about it. It's got a 351 cleveland. There is a miss which i think is caused by a bad valve in one of the cylinder heads. How much could that effect the speed?

depends, you might have more vacume leaks than you think, i'd check the compression on all the cylinders, you might have a blown head gasket, i'd also think about replacing the distributor cap, rotary button, plugs, and plug wires

I have replaced all the vacuum lines, the vacuum advance, distributor cap and rotor, and plugs and wires. I also set the timing and adjusted the carburetor. Theres nothing wrong with the vacuum lines now.

then you might have a blown head gasket, you're loosing compression somewhere, at least that's what it sounds like to me, theres a little gage thingy that you can buy, i can't remember what the name of it is, you screw it in where your spark plugs are and disconnect the distributor so the engine isn't getting any fire and you turn the engine over to check the compression on the cyilders, if you have good compression on one cylinder and another has compression lower than the good one, then you have a blown head gasket