Drilling heads for offset header bolts

Steven · Dec 3, 2008

As i'm trying to decide what to do with the mustang, i've lined up a set of coil overs and a tubular K for 150 bucks. Since I want to smooth the engine bay I figured i'd redo the whole front of the car. Because of that, I may as well build the motor, or a motor, for it as well as pump up the 5 speed. I currently have two sets of heads at the moment, one sets windsor, ones 302. Twisted wedges are my 302 heads, just standard with stud mount rockers, and then I have a set of seriously ported, high horsepower applicated 351 windsor heads. I also have a set of hook 1 3/4" longtubes with 3" collector from my race car. The problem is both heads are standard side by side bolts, while my headers are annoyingly offset and require the piece of crap adapter plate hooker sends along with there windsor swap headers. I'm interested to see if its possible to drill my heads for my offset headers so that I can use their full potential instead of bottle necking them with those plates. Another question is, I have the ability to trade off my twisted wedges. I'm hesitant as I don't know if I want to go with a windsor swap to utilize all of my parts. Just wonder how difficult it is to put one in a 95 from the stand point of parts and money. Theres nothing mechanically above me that I can't do as I've done almost everything except for FI work. Almost seems like if I have the motor out I may as well build a windsor and toss it in there. It's not my daily, nor do I plan it to be. Just a fun car. I'm worried that the 302 will leave me wanting more quickly and all it has to offer is a junk block.

ddrracing · Dec 5, 2008

Theirs no reason that you couldnt drill and tap some holes. Just curious, what kind of "high horsepower" windsor heads do you have?

Steven · Dec 5, 2008

Edelbrock victor series that have been ported by bennet racing. They are 7k and can sustain as much as you want.

ddrracing · Dec 5, 2008

Very nice heads. :thumbsup: I'm currently recycling an old race engine for my 95 vert, using a set of motorsports E351 heads.

Steven · Dec 5, 2008

wow, old school. Lol. The general plan for the car is a windsor, as to whether its built with street, strip, or road course in mind, is still up in the air.

ryclef331 · Dec 5, 2008

NO NO NO NO NO. You don't know that there isn't a coolant passage behind where you're going to drill. The plates are not a bottle neck! If they're the same size as the exhaust ports on the heads and headers, there is no "choke" point. If they're smaller, open them up! DO NOT ruin a set of heads by drilling them

Steven · Dec 5, 2008

Thanks for clearing that up ry, i figured as much but it's always worth asking

tommybunz · Dec 7, 2008

just sell the headers or trade

LAFENATU · Dec 7, 2008

ryclef331 said:
NO NO NO NO NO. You don't know that there isn't a coolant passage behind where you're going to drill. The plates are not a bottle neck! If they're the same size as the exhaust ports on the heads and headers, there is no "choke" point. If they're smaller, open them up! DO NOT ruin a set of heads by drilling them

I was thinking the exact same thing until I saw your post...

As I was reading I was like "Nooooo!!!" lol

ddrracing · Dec 8, 2008

If your halfway competent and examine the head carefully, it's not that big of deal. I understand your concerns though, but its not impossible.

Steven · Dec 8, 2008

I wasn't planning on it but i've heard of people having it done. I believe in some cases, mainly windsor heads, you can have it done if they specify that it can. Who knows, i'm not worried about it. I'm probably selling the heads anyway lol

LAFENATU · Dec 8, 2008

ddrracing said:
If your halfway competent and examine the head carefully, it's not that big of deal. I understand your concerns though, but its not impossible.

Impossible no it is not.

Not that big of a deal??? Oh hell yes it is. If you hit the coolant passage your up shits creek. That head is done, you could never seal up that passage correctly again.

ddrracing · Dec 9, 2008

No big deal, meaning its not big deal for person to do their homework before going to town on it.

Steven · Dec 9, 2008

psh I wasn't going to do it, take it to a machine shop, that way its there ass if they say its alright and they mess up my pretty trickflow heads... lol.

ryclef331 · Dec 9, 2008

Why pay MORE money to drill, permanently modify, and risk ruining a perfectly good set of heads when you can run adapter plates that in NO WAY hinder performance? Think about that before you suggest modifying a head...vice running the adapters

Steven · Dec 9, 2008

ryclef331 said:
Why pay MORE money to drill, permanently modify, and risk ruining a perfectly good set of heads when you can run adapter plates that in NO WAY hinder performance? Think about that before you suggest modifying a head...vice running the adapters

Yea exactly. I simply asked because our victor serious ported heads exhaust ports are extremely large compared to the plates, and provide serious bottle neck.