Getting the most out of GT40Y heads?

ES Stangin

New Member
Apr 6, 2005
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Erie, Pa
Well I recently found out that the previous owner installed a set of the GT40Y heads with crane arm rockers, etc. (meaning I dont know what else)..

Since I didnt pay for these.. is it worth it to have them worked over? What exactly should be done to them to make them better?
 
Sell them.

Take that 500 you would have dumped into them and put that into the pot that you get from selling them, and buy decent stuff.

Even after all the work you put into them, they'd be hard pressed to run with an AFR/Edelbrock/TFS head.

Joe
 
John uses a figure of 300

and

Joe uses 500

I would wanna know what you really could sell them for

and

how much it would cost to get more performance from them.

I would see the method of more performance work something like port size increase, bowl work, milling, etc. This kind of work ain't cheap but I really don't even know a ball park price. :(

Bottom line here is like anything else I guess

Does the buck spent justify the gain received :shrug: :shrug: :shrug:

Grady
 
my question is: if all our stangs came with alum Y303 heads, how many of us would rush out to buy AFR/TW/Edel heads?

I for one would not. after seeing all the dyno runs popping up with P heads hittin 290+rwhp i don't think putting a small amount(under $550) of money into Y303 ALUM heads would be a bad idea.

i have a feeling that with a blower and mild ported/valve job Y303 heads you could max out the stock block.
 
My car went plenty fast with the X heads box stock. The Y's can make power if done up right with a good cam. Its a different ball game when your right there with the AFR/TFS/Eddy cars. Its good to be different.
 
I was just going by what all that work costed me. I just pulled my invoice and my bill total (with flow testing) was $350. To be honest though, I think he cut me a break of $50 since I was bitching that the work took a month longer than expected, AND I didn't need new guides.
 
Leave 'em!

If it runs good, leave them the way they are. You have a great combo going. You have a great intake, solid heads, just add:

-mild cam
-mid-pipe
-3:73's
-#24's/MAF
-tune


Your car will be a blast to drive. If it aint broke don't fix it.
 
The only problem is that my combo doesnt seem to be netting good results. The last time I was at the strip I ran a 15.2 @ 92mph with a 2.3-2.4 60ft. I was kind of disappointed finding out that it had aluminum heads and wasnt running as strong as it should. The car does occasionally run roughly and likes to die out, so maybe something else is wrong.

What should (estimating) the car be running with my setup?

I definately need an O/R X or H pipe, and maybe a new MAF since mine was covered in k&n crud for years..
 
ES Stangin said:
The only problem is that my combo doesnt seem to be netting good results. The last time I was at the strip I ran a 15.2 @ 92mph with a 2.3-2.4 60ft. I was kind of disappointed finding out that it had aluminum heads and wasnt running as strong as it should. The car does occasionally run roughly and likes to die out, so maybe something else is wrong.

What should (estimating) the car be running with my setup?

I definately need an O/R X or H pipe, and maybe a new MAF since mine was covered in k&n crud for years..

Well, you should definatly be runnning a bit faster than that. But you must remember that stock vert/aode's are 15.5 cars. With stock injectors, no tune, and stock gears, a 15.2 isn't out of the question for a car that heavy, and I'm sure you could have gotten her in the high 14's with good conditions, a good launch, and some easy weight reduction.

You have some big mods (Heads, Intake), but nothing done to support them. More Fuel, MAF, cam, tune. Your car will feel 10x's better. With gears, there is no reason you can't be into the 13's. Pullies, mid-pipe, torque converter with drop your times even more.
 
See sig. Box stock Y303s. All mods listed. The heads gave me a .4sec in the 1/4. My best 60' is 2.0. Overall I am happy with the choice I made with these heads. I have suspension mods planned and hope to drop my 60' times down. I also plan on a catted X-pipe soon.
 
So instead of having the heads ported (which Im glad Im not because Im already in over my head with how much stuff I need to put back together).. I will work on the supporting mods and go from there..

Would it be alright to get a MAF and injectors and run them without a tune for now? I dont really have the money for a Tweecer or PMS at the moment, and a chip wouldnt work well because of the lack of a decent tuner in NW PA (plus getting a reburn for every mod I add is tedious). Also, would it be wise to use 24s and just change them out when I add forced induction or should I start higher and go from there? Thanks a lot for the help! :hail2:

*I guess now I could answer my own question in that a tune should go with the MAF and injectors*
 
If you already have the car torn down........ I would go ahead and order up a custom cam........ that the way you are gonna get the most performance out of those heads........

If it is torn down some now..... go ahead and do the cam and the mods after that will all be simple bolt ons. This way your car isn't down anymore.... pretty much any mod after that is just electrical or a couple of small bolts or something, not pulling intake, etc...


jason
 
Most of the performance gains are from porting work on the bowls.They are really nice torquey street heads due to there somewhat small ports. But no doubt,the AFR's give you the best of both worlds -street and track.MM and FF a few years ago did a comparison of the various heads and the out of the box Y's stood in there pretty well with most of the heads until you got over about 5200 RPM.They did very well below 3000 RPM.With the porting work I had done and improved static compression (higher compression pistons) I am very satisfied with these heads for how I drive my car;only on the street..