Engine Ported Gt40p's??

PakstinN

Member
Jul 17, 2014
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Hey boys, a short while ago I had the misfortune of snapping the crank in my gt40p headed 302 (how/why it snapped I have no idea) so I am currently going through the rebuilding process to get her back on the road..I already have a shortblock all done up and ready to go..HOWEVER, when the crank snapped I bent a few valves so I sent the heads off to get new valves and then the guy doing the work for me says he wants to put 1.94/1.60 valves in my heads and port them for me for $200..hes done a couple sets of P heads and has flow bench tested them at 239 [email protected] on the intake..my question is will I feel a noticeable difference after getting them ported, would there be any dangers associated with porting these heads (exhaust side too open..too much heat?) and will I need to get my explorer intake opened up more to support the extra air? I already have a bigger cam, obviously I have all the explorer stuff, and I have long tubes, off-road H and super 10s..so I'm not really worried about choking the thing on the exhaust side..any input is much appreciated..thanks!
 
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$200 for bigger valves AND port work? Normally the answer is do not port the iron heads, but at that price when you already need the work, I say go for it! I hope he knows good valve head and seat angles for great flow.
The Exploder intake I have is ported. The lower was ported by tmoss, and looks like golf balls would flow through it. I matched the upper to the bigger TB and continued opening up (thinning and smoothing the bolt intrusions) as far as I could reach.
So for $400 or so, I bet you could feel it. It may not be a huge gain but it would be better than regretting not trying it for that amount of $ when it is apart.
 
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I suppose the only other option I can see would be going out and getting a set of aluminum heads..I saw something about patriot aluminum heads on another forum..the guys seemed to like them..any thoughts there?
 
I did the same thing on porting my gt40ps even the upper lower intake you would feel alittle more gain . You will feel the difference but you shouldnt really worry about anything you will be good
 
The price sounds too good to be true.
A valve job alone without parts is usually around $200.
Now you add new valves (at a minimum) and port work?
Your bill should be drastically more than that.

Forget patriot heads, they are garbage.

If you only want to change the heads once and be done, see if you can swing a set of Twisted wedges.
Afr 165's are really good too, but they are a few hundred more than the tw's.
 
Right. I really like the twisted wedge heads but college has me on a budget..the only reason I’m getting all this work done for that price is because the guy is a friend of mine and he has most of his own tools to do it himself
 
Porting heads is or intakes are not hard its really simple but if you say he is a friend I say go with the idea and get them ported ! But like 200xp8 said you can get better heads for a little more buts it all on your budget
 
when people say I might notice a little difference, is there any way to gauge how much power I'll actually get (assuming everything is done right) something in the neighborhood of 15-30 horse? whats a good estimate?
 
It really depends on the quality of porting, valve job and supporting parts. TMoss on the lower intake and a matched TB/EGR will really help.) But if I had to put a number on it, i’d say you are in the right range. And it should be felt in the entire, enjoyable driving range without hurting streetability. And that’s pretty good for your budget and situation.
 
Alright I’m well aware this thread has been dead for awhile, but I just got some info some of you might find interesting. These ported gt40p heads with a carb intake and comp 270 made 351/375 to the crank on a 302, I thought that was pretty awesome
 
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Yep! Got the heads back yesterday, got my ed Curtis cam installed yesterday, checked PTV yesterday, and today I will measure pushrods. I do have a question about checking PTV and pushrod length though. Most kits come with a roller lifter that got modified to be solid..well I didn’t get one...aaaand my machinest said it was unnecessary..so when I was trying to do PTV I ended up just taking the adjustable pushrod and screwing it out so it bottomed out the plunger of the lifter so there was no slack in the valvetrain..when I measured it, the valves weren’t even close to the Pistons..something in the neighborhood of .300-.400..is that an acceptable way to check PTV clearance? Also, does anyone have any tips on how to measure pushrods if I don’t actually have that modified lifter? I figured I would just base my measuring off of lifter preload (pushrod ever so slightly depressing the lifter plunger)...is that the way to do it or am I all wrong? Thanks