So from what I've been reading the 5.0s have square ported intakes lower and upper and the 5.8s have the round. Well my 92 5.0 does have the square on both lower and upper. My 351w I just got to swap in has square lower intake ports but the upper intake was round. And I know the upper was a 5.8 because it has the ford EFI 5.8 logo. But is the lower a 5.0 because it's square? I thought the 5.0s wouldn't fit a 5.8. So is it possible I have a 302 with a 5.8 upper intake on it? Because I bolted my original 5.0 upper to the new 5.8 lower and fits perfectly. Just looking for some input because I'm don't know that much about these intakes, thanks for any help

 

Lowers do not interchange. Measure across your manifolds, you'll see the diff.

 

That's what I thought. So is it true all the 5.0s are square and 5.8s are round?

 

Yes you have been duped, a 5.0 lower will not bolt to a 5.8 block because it is taller and wider so the heads are also further apart. You can ID the block by examining the area where the distributor plugs in, if the surface is roughly level with the intake gasket surface you're looking at a 5.0 while if it's about an inch below the gasket surface it's a 5.8 block.

A 5.0 Block..



A 5.8 Block...

 

What you were reading was pertaining to the upper/lower intake mating surfaces only. The head ports of the intakes are rectangular for all 302/351W's (except for the old Boss 302 which had Cleveland style heads)

 

The mating surface between upper and lower intakes are same size, but the ports are different..

5.0 are square and 5.8 are round.. Aka gonna cause a cluster**** if even attempted to bolt up and run..

 

Explorers and some other 5.0's have the round opening on the lower in a staggered pattern.
Dave

 

Those 5.0'S with the staggered intake ports have the GT40 or GT40P heads and were given the "Cobra" style intake which matches the better flow of the GT40 heads.

 

Here are the three 5.0 lower intakes left to right, first is the 5.0HO, truck intake in the center and then the Explorer/GT40 on the right. Obviously you cant mix parts between these, matching upper and lower portions must be used together.

 

Thanks Conanski it is definitely a 351. And yeah i just have the standard middle truck lower intake. But my 5.0 upper intake works just fine on it, im not sure what all the talk I have heard and seen on it about a 5.0 upper not working on a 5.8 because it works fine. Thanks for the input guys

 

Also just dont understand why Ford would make the large square shaped ports on the lower and then the small round ports on the upper for the 5.8 lol. My 5.0 upper ports match the lower ones so im sure it has alot better airflow than those small holes of the 5.8

 

If the motor you got has the lower portion on the left you have a 5.0 motor not a 5.8.. that lower portion will not bolt on a 5.8 motor the lifter valley is too wide.. the 5.0 intake is only about 9" wide while the heads are about 11" apart on the 5.8.

 

I do have the one on the left. But it is a 5.8, at least according to what you said Conanski. The distributor area sits an inch or so lower than the 302 block I have. Also the head bolts are bigger. And it is a wider heaver block. So how do you explain that lol if its not a 351 and its not a 302 than what is it?

 

Post the casting numbers of the lower you have. If you truly have what you say you have, it's truly a one of a kind. Ford's been known to do strange things, this would be yet another.

 

Nevermind Conanski after further measuring and searching it is a 302. Sorry bout that. Well dang id be pissed if i paid for the engine lol but a free 302 is as good as a free 351 lol so oh well