any clearance issues using gt40 heads?

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any clearance issues using gt40 heads?

June 06, 2015, 04:55:59 PM

I'm looking to swap my e6 heads for a pair of gt40 heads as well as a gt40 style intake and 65 mm throttle body. Do you think there will be any piston to valve clearance issues with the stock SO camshaft and the heads?

Also, later on I will probably do the full HO conversion, but for now do you think this setup will work?

any clearance issues using gt40 heads?

Reply #1 – June 06, 2015, 11:18:24 PM

I don't believe there will be any to worry about. I'm unsure of the lift specs on the SO cam, but, if I'm not mistaken, the HO cam advertised lift is .444 intake. Now I know duration plays a big role in ptvc as well. But I am running gt40p heads, intake, and I have an FRPP F303 cam with .512 lift. No ptv issues. I would suggest maybe rockin the HO cam (if you can get one cheap) with your factory rockers. Should do pretty well. But back to the original question, I doubt you'll have any issues with the SO cam. Better wait for input from others with more experience. I'm still a bit new to game myself. Best of luck!
Cheers

any clearance issues using gt40 heads?

Reply #2 – June 07, 2015, 06:15:22 AM

+1 On the HO cam...Pretty cheap if you find a used one. But I understand if youre on a budget and doing it in steps..I have been collecting parts for awhile to do my HO conversion.

any clearance issues using gt40 heads?

Reply #3 – June 07, 2015, 01:00:03 PM

Thanks for the info Fox, and yes I probably will end up getting an ho cam at some point, but in order to do that wouldn't I also need to change the timing, get a new ecu, injectors, fuel pump etc?

any clearance issues using gt40 heads?

Reply #4 – June 07, 2015, 01:44:07 PM

Yes, to do the HO swap properly, you'll need an EEC from a 5.0 Mustang, the 19 pound/hour injectors, and the HO cam. To maximize the power, I'd also suggest at least the HO headers, or aftermarket...1-5/8" would be great, especially if you're going to up the power later. With P heads, you'll want to get specific headers, as the plug angle was changed on the P's, most headers won't clear 'em.

The other thing to think of is Mass air vs Speed density. Again, if you're going to go with anything beyond stock heads and cam, you'll almost have to have mass air. Sure, one can tune a SD combo, but plenty of A9L, A9P eec's and you can almost get a mass air meter at wal mart nowadays...

I also have a couple of HO cams, but no other engine parts.

PS, an HO cam, with GT40 heads will work with the stock SO pistons, anythign with higher lift will almost certainly require the pistons to be notched, or else a set of HO pistons. Best bet would be to putty the pistons and be sure there's no contact...valves to pistons will definitely wreck your day and wallet.

any clearance issues using gt40 heads?

Reply #5 – June 07, 2015, 09:09:21 PM

Here is another link that is very helpful. You may already be utilizing this, but it helps alleviate many other concerns along the way. I used this website multiple times for my little tricks on my car. Still would be lost without the awesome knowledge of others. Lol. Hope this helps.
http://www.coolcats.net/modifying/ho_conversion.html

any clearance issues using gt40 heads?

Reply #6 – June 08, 2015, 10:33:21 AM

http://ls1tech.com/forums/generation-iii-internal-engine/1155880-how-flycut-pistons-ls1-free-almost.html

Do this ASAP and get it out of the way. Then you're ready. Mark your stems with a sharpie etc, measure it up and cut a little extra beyond what your lift should be. Check it all up a few times. Go slow, the sandpaper marches through aluminum quick!!!! You'll find that you need to cut surprisingly little out of your flat-tops for this. Then you won't have to worry about balance issues. Did this on my red cougar, and I have absolutely zero undesirable vibration even wide-open hitting the limiter.