Thinking about buying need help

[Poseidon]

Im looking at a 1988 lx 5.0 5 speed the owner says it has 351w heads and the cam does anyone know if anyone else has done this he says it get 14 mpg but that's what you'd get with a complete 351w .
ive never seen 351w heads on a 302

 

[ALMOST STOCK]

351w heads and 302 heads are basically the same with the exception of the head bolt diameter. 302 heads have a 7/16” head bolt hole and the 351w has a ½” head bolt.

 

[Poseidon]

so no real advantage of them

 

[ALMOST STOCK]

Nope not a big advantage.
Late model 351 heads flow the same as the 302 so if you are upgrading the heads the ones to get are the early style.... But the difference are the bolt size on a 351 windsors are 1/2" and they are 7/16 on 289/302...late model heads have 1.78 intake & 1.46 exhuast valves and early ones have 1.84 & 1.54 & also slightly larger intake and exhaust runners.

Ford began using the same basic head casting for both the 302 and 351W in 1977.

 

[Poseidon]

okay thaks i wonder why the gas mileage dropped then?

 

[ALMOST STOCK]

I don't know why but I've read more than once over the years of people only getting 14-15 MPG on there stock Mustang.
I get about 19- 20 MPG in my 89 and the best I've ever gotten has been 24 MPG and that's been since April 89 when I bought it new.

 

[Poseidon]

okay thanks for the info