Ford guys... header question, 89 5.0/302

[NotMatt]

Working on a 89 302 bronco project right now, motor is the original fuel injected 5.0. Stock manifolds were both cracked, driver's side came off in two pieces. I have two different pairs of shorty headers I can pick from to replace them, but I'm seeing differences in the exhaust port size on them. The first picture is a set of Hedman shorties that I WANT to run, with a more square exhaust port. The second picture is of a pair of pacesetters that will require a bit of massaging to one of the outlets, but the exhaust port is more rounded, and matches the size of the exhaust port on my heads a little better.

I'm going to run Percy's dead-soft aluminum gaskets that I got for the round port 5.0 heads. My question is... can I run the square exhaust port headers on my heads with round'ish/oval ports? Is there enough surface area to seal up the gasket on the round port heads, or am I asking for trouble? Anyone have any insight here, I know there's a few Ford guys on here. :redneck:

Square Hedman headers:

Rounder/Oval Pacesetter headers:

 

[crapyota]

My heads on my 5.0 are more oval, and i have always bought the cheap flowtech headers(couldnt justify expensive headers)wich Match those hedman ports..if you look at the pics it looks like the hedmans have more surface contact around the bolt holes then the oval ports..

I have always cut my gaskets to match the ports as much as I cann. Last time it was a
Part I fully gasket matched head,and header. post up a pic of gasket maybe...


I personally have never had an exhaust leak on any of my 5.0's(4 of them) at the head. Usually be one in the dang cheap h-pipe designs at the crossover..just my experience with 5.0 headers not much info but hope helps a lil..

 

[zukkev]

Just fill in the corners of the square hole headers slightly with that metal melting device to make the ports more oval-shaped, and message it flat again with that metal removing device so it don't leak!!! :redneck:

 

[NotMatt]

Just fill in the corners of the square hole headers slightly with that metal melting device to make the ports more oval-shaped, and message it flat again with that metal removing device so it don't leak!!! :redneck:

That's exactly what I decided to do last night after posting this, then thinking about it some more laying in bed. The corners are the only place where the headers appear larger than the ports on the head, so it should only take a little bit of fill in each corner, and some careful flap wheel and die-grinder work to clean it up and match it good to the gasket.

Edit: make that, the corners are the only place where the headers appear to be ALMOST as large as the opening in the head, leaving little flange area to seal the gasket. They are not actually TOO big for the ports, just very close.

 

[Totalled]

I was not impressed with the percy's gaskets. Oval port gaskets + rectangle flange = Tick tick tick tick tick tick tick tick. Even on stock explorer manifolds. I'd just run stock manifold gaskets.

 

[NotMatt]

Too late! Both headers are installed and torqued down. We'll see if they leak I guess, and I'll re-do with different gaskets.

These are mustang headers, so i had to clearance a wee-bit on the bellhousing on driver's side, and i'm re-routing the trans vent line and having a custom y-pipe done.

 

[Glenn]

:bling: :bling:
So shiny I had to put my sunglasses on.

 

[messix]

a slightly larger port on the header flange and tube than the head creates a anti reversion effect to improve lower rpm power.

that said I would use the gasket that matches the header port.

 

[Not Jobless]

I ground my 5.0 heads to match the exhaust manifolds and gaskets. You can remove a **** load of metal.

 

[Totalled]

Yeah, if you have the heads off, removing the thermactor bump and gasket matching helps tons... Tiny little sbf ports.

 

[NotMatt]

Yeah, if you have the heads off, removing the thermactor bump and gasket matching helps tons... Tiny little sbf ports.

They certainly are small. I ditched all the smog pump **** and plugged the back of the heads, am kinda wishing I had just pulled the heads and done a refresh and some cleanup on the exhaust ports and removed the thermactor bumps like you said... I was that far into it basically with the intake off and the manifolds off, just didn't want to dig deeper and find more "issues" to fix. Oh well.

 

[Totalled]

I'd just put a set of GT40s from a 96/97 exploder on it if the heads had to come off... Or the whole long block.... :corn: