Buying GT-40s from board member, what do I need to know about freshening/machining?

[Hobie]

Trying to keep this a cheap project, don't want to have enough money to buy real heads wrapped up in these.

Honestly, I don't even care about absolute peak hp or ets. I just want the heads to operate like new, make more power than a set of stockers would, I would like to add some compression because I like the way it makes the motor sound, and I would like to mildly port the heads myself.

The shortblock is fresh. std bore, stock replacement forged pistons, the intake is a GT-40 w/ported lower, has an e-cam for now. Thinking of going for a tfs stage 1 or andersonn n41 cam later.

The heads are early explorer (pre gt40p) 3 bar GT40s from a junkyard.

One of my buds is a machinist for an aerospace defense contractor. He's a bit of a car guy and said he could media blast and mill them no problem.

Questions I have

I've put heads on a fox a couple times before, but the last time was over 10 years ago. Would milling the heads require the lower intake to be modified so the bolts line up or is there that much play in the lower intake bolt holes?

What about the bottom of the lower, do you have to machine that too if you mill the heads?

Will I need a different length push rod after milling the heads?

Thoughts on this spring kit?

http://www.alexsparts.com/sb-ford-gt40-drop-in-valve-spring-kit-hyd-roller/

What all special tools will I need?

What else do I need to buy to freshen the heads?


Anything else I need to know, but didn't mention, yeah, tell me that shit too.

[Vertnut]

I had a set that I had cleaned up (vatted/decked/fluxed), valve job, and pocket-ported on the exhaust side. For the money, they did a nice job.

[onjacks]

Get a valve job. Order the trick flow spring kit for stock style heads. Mill just enough to get heads flat. Bolt on and go. Look for done used roller rockers too.

[Snatch Napkin]

It was good to meet you.

[46Tbird]

Trying to keep this a cheap project, don't want to have enough money to buy real heads wrapped up in these.

Honestly, I don't even care about absolute peak hp or ets. I just want the heads to operate like new, make more power than a set of stockers would, I would like to add some compression because I like the way it makes the motor sound, and I would like to mildly port the heads myself.

The shortblock is fresh. std bore, stock replacement forged pistons, the intake is a GT-40 w/ported lower, has an e-cam for now. Thinking of going for a tfs stage 1 or andersonn n41 cam later.

The heads are early explorer (pre gt40p) 3 bar GT40s from a junkyard.

One of my buds is a machinist for an aerospace defense contractor. He's a bit of a car guy and said he could media blast and mill them no problem.

You will have to put aftermarket valve springs in these heads. They were flimsy from the get-go and they will bind with the lift of an E-cam.

Questions I have

I've put heads on a fox a couple times before, but the last time was over 10 years ago. Would milling the heads require the lower intake to be modified so the bolts line up or is there that much play in the lower intake bolt holes?

No worries. There is plenty of play in the intake bolt holes to allow for any machining you will do.

What about the bottom of the lower, do you have to machine that too if you mill the heads?

Nope.

Will I need a different length push rod after milling the heads?

Maybe, but probably not. There is a lot of tolerance in the stock roller lifter plunger and the E-cam is not a radical profile, especially if you stick with a 1.6 ratio. All you can do is assemble the intake and exhaust setup on one cylinder and check it.

Thoughts on this spring kit?
http://www.alexsparts.com/sb-ford-gt...it-hyd-roller/

Looks good.

What all special tools will I need?

A torque wrench.

What else do I need to buy to freshen the heads?

These modern heads come with the good, positive intake valve seals from the factory. If the heads have been run anytime within the past year or two, they're probably fine. You might want to check them, but if I was doing this on a budget, I'd just stick with what's there.

Same for valve guides. Once you get into replacing these kinds of parts, you make a strong case for a new set of heads.

Oh yeah, these heads are pretty old now and have a million miles on them. Make sure ALL the valve cover and intake threads are good. Having them repaired starts costing $$.

Anything else I need to know, but didn't mention, yeah, tell me that shit too.

It couldn't be much easier. I bolted these onto a '66 289 and everything dropped right on like it was born there. All the accessory bolt holes lined up.
I had them milled quite a bit, .030" to get compression right around 9.7:1 with my C-code 289's dished pistons. Imagine my surprise when I found out the block was bored .060 over and the cast replacement pistons were flat tops. So it's closer to 10.5:1 but it runs pretty good. hahahaaa

Here is some must-read info about GT40 and GT40P heads: http://www.fiveohinfo.com/performance/gt40-gt40p.html