What do i need for GT40p H/C/I install

daryl_db

New Member
Jul 12, 2007
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I am in the process of installing some gt40p heads in the next couple of weeks. During this time i am doing a light port job cleaning up all of the areas noted in diyporting.com. What intake and head gaskets should i use. In the future i will be using nitrous so i want a headgasket that will take the punishment. Should i use ARP bolts or studs.

I am going to use a gt40 tubular manifold and a e303 cam. Do you think that this will be a good combo.

Thanks for looking.
 
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Bolts are fine for N/A. Studs are nice for blower combos.

I would use a FPP-1250, the FPP-1250S is a bit more expensive but will last longer. The regular FPP-1250 can last a while as well.

Click on the link in my signature, about the H/C/I swap. It is helpful in giving you parts and gasket numbers, tools needed, and the procedure.

Good Luck and your combo sounds just fine:)
 
Intake Gaskets : Fel-Pro 1250 (previously mentioned) or equivalent
Exhaust Gaskets : Fel-Pro 1415 or equivalent

Nitrous is a type of forced induction (when it is being used) and should, in ideal world, utilize similar gasket retention hardware as to a blower or turbo setup.

Ideally, ARP head studs with Fel-Pro Loc-Wire head gaskets. You would have to have the GT-40P heads machined to accept the Loc-Wire head gasket, because they are not already o-ringed.

In my opinion the GT-40 is a good manifold that gets respectable horsepower numbers while maintaining excellent torque numbers.

If you were running a N/A setup permanently, you could stick with the GT-40P heads and E303 cam. The setup wouldn't wow anybody with power figures, but it would be a good reliable performance oriented street car. Once you start running nitrous, the E303 cam and GT-40P heads will work, they just won't make as large of power numbers as other components.

FYI, from the factory, the GT-40P heads have single valve springs with no damper, only rated to .450 lift. I hope you have installed new springs that will support your single pattern .498 lift of the E303 cam....coil bind would suck :nono:

My personal .02:

You could keep the GT-40 intake, have the lower ported to increase flow. I'd rather run a better set of heads, and if you decide to go with Fel-Pro Loc-Wire head gaskets like I recommended, why not get a great set aftermarket heads like Edelbrock Performers/Performer RPM or Trick Flow Twisted Wedge (they have part #s available that are ALREADY o-ringed for Loc Wire head gaskets).

If you can't afford better heads, at least get a better cam. The E303 cam, like all of the "alphabet" cams, are ground by Crane. I've even had a Crane rep tell me over the phone that Crane doesn't like the E303 cam.... I wouldn't use a cam the manufacturer themselves aren't even proud of. What I would do instead? Have a custom cam ground for your finalized setup. Camshaft Innovations or Flow Tech Induction are two good custom cam companies. The car will drive better, make more power, and match your exact setup. What more could you ask for?
 
Thanks guys for your feedback. I am going to upgrade the valve springs with TFS springs. I would love to upgrade to better flowing heads and a custom cam but money is tight.

I have to also keep this setup emmisions legal. Can you get a custom cam that still is legal. Is in really going to be worth the extra money?
 
Yep, a custom cam can be made emissions legal. Just let them know:)

They cost in the $325-$350 range.

They not only help out in performance, but driveability, emissions, vacuum, idle quality. It isn't a bad way to go for an extra $150 or so dollars.

If your on a nice little budget, it's okay not to have a custom cam:nice:
 
Thanks guys for your feedback. I am going to upgrade the valve springs with TFS springs. I would love to upgrade to better flowing heads and a custom cam but money is tight.

I have to also keep this setup emmisions legal. Can you get a custom cam that still is legal. Is in really going to be worth the extra money?

yes it is worth every single penny, I will never go with an off the shelf again. My car drives better, has a wider powerband, makes more power and pulls higher.
 
My 93 has a P headed combo. I ran FEL 1250s for the intake gaskets and FPP 1011-1 or 1011-2 for my head gaskets. I can't remember which one as it has been a while since I put them in.

Anyways specs are this

Box stock P heads with TFS spring kit
TFS stage 1 cam (should have gone custom but I got a killer deal on this cam)
TFS trackheat intake
Scorpion pedestal mount 1.6 rrs
Full exhaust with FRPP ceramic shorties for the P heads
TFS wet plate nitrous kit

Keep in mind that this car has a beat up AOD in it with the stock converter so my times aren't going to be as good as a 5 speed car.

14.0s at 100 mph NA and 12.72 @109 on a 100 shot.

Not bad for a car that has been built with mostly ebay or used parts. :D
 
Some practical tips...

Cylinder head removal & replacement

Plan on 3 days to do the job if you haven't done it before.

Day one gets the heads off in 4-6 hours. Remove the A/C compressor mount bolts and move the compressor out of the way. The A/C compressor swings out of the way without disconnecting any of the lines or losing any refrigerant. Mark all the electrical, smog and vacuum lines with tags to help you remember where to re-connect them.

Day two gets all the gasket surfaces scraped off extra clean and the heads dropped off at the machine shop if you are going to have them reconditioned. Time here is another 4-6 hours. Whatever you do, don't skimp on cleaning the gasket surfaces. New gaskets need to seat against bare metal and not the residue left from the old gaskets in order to seal leak free. This is the most time consuming and tiresome part of the job. Look for little things that need to be replaced like the short hose from the thermostat hosing to the water pump, damaged vacuum lines and hose clamps that are rusted or broken.

Day three starts when you get the heads back from the machine shop. This is the time to pick up all the little odd pieces you found needing replacement on your day two inspection/cleanup. Plan on 6-8 hours to reinstall the heads and reconnect everything. Plan on an additional 2 hours to troubleshoot/adjust everything.

Now for some practical tips:

Plan on cutting the thermostat to water pump hose, or removing the thermostat housing. Also plan on removing the distributor to get clearance to remove the intake manifold. Remove #1 spark plug, stick your finger in the spark plug hole and crank. When your finger gets air moving past it, stop cranking. Turn the engine until the timing marks line up with the pointer. Make a scribe mark on the distributor base and engine block. Now you can pull the distributor out. When you re-install the distributor back in the engine, make sure you are still on TDC compression for #1 and then line up the scribe mark on the distributor and engine. You will be very close to where the engine was timed when you took out the distributor.

You'll need new head bolts - get ARP bolts ($40) or studs ($93, maybe more). The ARP bolts have a radius under the heads. The washers that come with the bolts have a chamfer cut in them. The radius under the bolt head mates up with the chamfer on the washer. Fail to do this and the bolts will never torque down properly. All the bolts get antiseize under the bolt heads, and everything but the short head bolts get it on the threads. You need Teflon pipe dope or ARP sealant to coat the threads of the short head bolts. The short bolts go into the water jacket and will seep coolant if you don't use the sealant.

My favorite trick that saves time and effort is the stay in place gasket. Be sure that you scrape (don't use a wire brush) all the old gasket material off, then clean all the surfaces with acetone or MEK.

When the surfaces are clean, use weather strip adhesive on the head to manifold surface, and on the side of the gasket that mates to the head. Follow the instructions on the tube or can and when it gets tacky, press the gasket down on the head.

Clean the area where the rubber rails mount to the block in front and in the rear with more acetone or MEK and do the same trick with the weather strip adhesive that you did to the heads.

Coat the rubber seals and the gasket area around the water passages with lots of Blue Silicone gasket sealer and put it together. Walla! No leaks and no gaskets that shifted out of place.

If you reuse the injectors from your old setup, a repair kit is available from most auto parts stores if needed. Coat the injector body "O" rings with oil before you use them and everything will slide back together.

For iron heads, clean the combustion chambers with a wire brush in an air or electric drill. I used a scraper for the pistons. I don't like to use the wire brush on pistons because it will remove metal very easily.

Change the oil once you get everything back together. Once the engine is up & running, run it for 1-2 hours and change the oil.

Tools: a good torque wrench is a must have item. A razor blade scraper that holds a single edge razor blade from Home Depot or Ace hardware is another handy thing. Get a Chilton or Haynes shop manual - you'll need it for the bolt torques and patterns. The intake manifold has an especially odd pattern. You'll need access to a timing light to set the timing after you re-stab the distributor.

Consumable parts:
Fuel injector seal kits with 2 O rings and a pintle cap (Borg-Warner P/N 274081) are available at Pep Boys auto parts. Cost is about $2.74 per kit. The pintle caps fit either injectors with a pin sticking out the injector end or 4 with more tiny holes in the injector end. The following are listed at the Borg-Warner site ( http://www.borg-warner.com ) as being resellers of Borg-Warner parts:

http://www.partsplus.com/ or http://www.autovalue.com/ or http://www.pepboys.com/ or http://www.federatedautoparts.com/

Most of the links above have store locators for find a store in your area.

Head gaskets
upper manifold gasket
lower manifold gasket set.
Exhaust manifold gasket set
Rocker cover gaskets - look for the rubber ones with the steel bushings - Summit has them
Short formed hose between thermostat hosing and intake manifold
6 ft 7/64" or 1/8" vacuum hose
2 ft 1/2" heater hose
1 1/2 ft 5/8" heater hose
Blue Silicone sealer
ARP antiseize or equal for the bolts
ARP thread sealer or Teflon pipe dope for the short bolts.
4 each 3/4" hose clamps (spare item in case the old ones are bad)
4 each 1/2" hose clamps (spare item)

Machine shop charges will vary - figure $275-$350 to have heads checked for cracks, cleaned, surfaced, valves ground, valve guides reconditioned, valve springs checked and bad springs replaced.
 
wouldnt he also need diff headers or something cause the way the spark plugs are angled. I was going to do the swap when i had mine and i remember hearing this from someone :scratch:

To make your life easier down the road then yes he should swap to p specific headers. For shorties I believe that only FRPP and MAC make p specific headers. If you have time you can usually find a set on ebay for a lot cheaper than new. I picked up my jet hot coated FRPPs for about $175 shipped and they were new.

Some guys have been able to make it work with out the p specific headers by using 90* plug boots and shorter plugs and modified spark plug sockets. To big of a pain for me. I would just suck it up and buy the headers if you want to swap to the p heads.
 
First off, I want to say thank you for all your feedback. After hearing about getting a custom cam I will take this under consideration. I am going to try to get some additional money together for this.

I currently have long tube headers but I am unsure about the manufacture. I guess I will have to do some trial and error to see if my headers will fit the GT40p heads.