Need advise on increasing HP a little more

[prairiepegger]

I have powered my first 23 with a 1999 5.0 liter ford engine. Went old school with a 600 holley, Performer intake and headers. 9" rear end with 3.10 gears. Opted for an HEI distributor.
This engine is stock and was rated at 215 HP when configured in the Explorer. These have the GT40P heads and was wondering what my options are to get another 35 to 50 hp out of it.
I like the low end torque but wish it could pull a little more out of the gate. This will not be a strip toy but would like to know that it could do 12's in the 1/4 mile. I advanced the timing an extra 3 degrees and it seemed to give me more off the line pull.
I've done some internet research to see what I can do to increase power to get close to 300 hp but the articles offer too many options and it's got me at a halt. Here are some of the options I've read:
1) Change cam and head springs
2) Port the heads, replace the cam and head springs
3) Some say that if I were to keep the current cam and just change the rockers to 1.7's and springs, it will provide almost as much improvement as changing the cam.

What do you think? I like option number 3 but I don't have enough experience to say if this is possible.
Thanks in advance.

 

[Hotrod46]

I'll go on a limb and recommend that you ditch the 3.10 gears and go with something like a 3.5 or 3.73 before you do anything to the engine. That will go a long way toward waking up a lazy car. Besides, if you go with more cam, you'll probably need more gear anyhow.

Also, after the gear change, retune the transmission governor to hold the gears longer. Most likely, the trans will "short shift" with the higher numbered gears. Reprogramming the gov will keep allow the engine to spin higher before shifting.

Do this and you may find you don't need engine work.

My 2 cents.

Mike

 

[Hotrod46]

Waited too long to edit my post. I would go with the highest numbered gear you can live with. 4.10's wouldn't be to high IMO. Spend your engine money on an overdrive trans and you can have the tall gears and still cruise the highway at a reasonable RPM.

 

[prairiepegger]

Waited too long to edit my post. I would go with the highest numbered gear you can live with. 4.10's wouldn't be to high IMO. Spend your engine money on an overdrive trans and you can have the tall gears and still cruise the highway at a reasonable RPM.

Thanks for the quick response. I never had to purchase or change gears before. Should be a fun task. What would I have to know for me to order the correct gears? I think my rear end has 28 splines - does this comes into play ?
I've also read that there is a "third member". Is this part of the gears I need to purchase.
I've copied and pasted an image. Are these the only two components I would need?

 

[Mike]

Obviously, there would be some ancillary parts required - pinion bearing, crush sleeve, any other bearings that might need replaced, etc. You'll not know their condition until you start pulling things apart.

 

[railroad]

If you have an overdrive trans, 4.10s will wake it up. For a non overdrive, I would go with 3.73s. I run 3.73s with a C-4, but my tires are about 31" tall and can still cruise with them. The 9" third member allows you to take the work to someone else, if you are not comfortable setting up the gears and preloads. The third option you listed is a good one. It will increase the valve lift, but not change the cam duration, which leaves the low end torque at a lower rpm. New valve springs are good whether you change the rockers or not. Both changes can be done with just pulling the valve covers. BE sure to plug the oil drain back holes in the heads. Those valve spring retainer locks are small.
Forgot to add, with the longer rockers, to check you rocker valve stem contact.
On the axle spline, you will not need to change or buy anything. The ring gear carrier will go back in the axle with the new gears. If you drag your axles out carefully the axle seals will usually make the change. Most 9 inch gear sets come with a new crush sleeve and a new pinion nut. The pinion seal is easy to change, put a new one in. Be sure to transfer the shim behind the pinion bearing to the new pinion. Put some gasket sealer, RTV on the pinion spline and under the pinion nut. This keeps the lube from migrating out the spline and slinging out behind the u-joint. I will stop. The shop will probably be up on all this, but if you have any questions, do not hesitate.

 

[Mike]

The third option you listed is a good one. It will increase the valve lift, but not change the cam duration, which leaves the low end torque at a lower rpm. New valve springs are good whether you change the rockers or not. Both changes can be done with just pulling the valve covers.

Before you make that change, measure installed height on your cylinder heads, then determine coil bind height on your springs, to ensure you will have enough coil bind clearance for the longer rocker. Note: you need to measure what you have with your cylinder heads and springs, do not trust what some manual's author thinks you should have.

BE sure to plug the oil drain back holes in the heads. Those valve spring retainer locks are small.

I had to read this one, three or four times, before I caught your drift. Be doubly sure you remove whatever you use to cover the drain back holes, when you are finished with the job.

Forgot to add, with the longer rockers, to check you rocker valve stem contact.

As well as retainer to guide clearance.

 

[one finger john]

More boost, more fuel pump, more lead, more money !

YEAH ! HAPPY 4TH OF JULY !

John

 

[one finger john]

O.K. prariepegger, lets get down to reality. How much do you have to spend ?
Give us all a break and say how much you are budgeted. This includes parts, labor, solvents, sprays, lubricants, shop rags, and any and all taxes. By labor I mean paying some one who is qualified and capable of doing the modifications. And usually it means that the bill will be approximately 1/3 to 1/2 parts and 2/3 to 1/2 labor. Depending on which way the wind blows and the way the shop gets its profit margin. Course if the owner can make more on the parts (by keystoneing) then just reverse everything.
OR .... the owner may be a greedy bastid who is also a good tech and then you will get a good, expensive job. No, No ..... I mean an expensive good job.

MIKE, TELL HIM WHAT THE THREE VARIABLES ARE WHEN MODIFYING A CAR. YOU KNOW. CHEAP, FAST, AND RELIABLE.

John

 

[Mike]

John, I always heard it was fast, good, and cheap, from which you could pick two.

You can get it fast, and you can get it cheap, but it is going to be a pull pin, looking to fall out of a grenade.

You can it good, and you can get it cheap, but you'll always see your job pushed to the side, when a real customer walks in the door.

Or, you can get it good, and you can get it fast, but you are going to have to pay for the opportunity.

 

[prairiepegger]

O.K. prariepegger, lets get down to reality. How much do you have to spend ?
Give us all a break and say how much you are budgeted. This includes parts, labor, solvents, sprays, lubricants, shop rags, and any and all taxes. By labor I mean paying some one who is qualified and capable of doing the modifications. And usually it means that the bill will be approximately 1/3 to 1/2 parts and 2/3 to 1/2 labor. Depending on which way the wind blows and the way the shop gets its profit margin. Course if the owner can make more on the parts (by keystoneing) then just reverse everything.
OR .... the owner may be a greedy bastid who is also a good tech and then you will get a good, expensive job. No, No ..... I mean an expensive good job.

MIKE, TELL HIM WHAT THE THREE VARIABLES ARE WHEN MODIFYING A CAR. YOU KNOW. CHEAP, FAST, AND RELIABLE.

John

Thanks everyone for your responses. It seems a gear swap to 3.73 is most likely the route I will take first. It's currently matched with a C4 and Railroad says it works well for him and I'm also running similar size tires.
Not sure whether I will do the job myself yet. The decision simply boils down to time as there is a fair bit of business travel this summer. I really don't have a budget in mind. I started this project because I love building stuff. Simply for pleasure and self satisfaction. The project is at a stage where I recognize a personal need for more "umpf" out-of-the-gate. Based on current prices, this will most likely come in south of one grand. If done right, a small price to pay for what I believe will be a noticeable change. Wonder what I'll want next.......hmm?
Thanks again everyone.
Cheers!

 

[railroad]

Sounds like a plan. Be aware the 9" Ford gears have an endless choice of ratios. The 9" ratio is actually 3.70s, no biggy. If you have some of the older junk yards around, this ratio was in some of the 60's and 70's pickups, maybe even in sedans with 6 cyl engines and straight shift trans. I used to scour the yards checking axle tags and door tags for good ratios and locking rears. If you can find even a 3.50 ratio the swap is so easy, you can work your way to the perfect gear. The only variables you will have to check are the axle spline and the pinion flange. The whole set up, sets in the axle housing, button everything back up, add dope and hit the road. The older axles were mostly 28 spline. The pinion flange can be swapped out and torqued down to set the bearing preload with the old crush sleeve, most of the time. These and the 8" Fords seem to be easiest to work on.
If you get to crawling under, eyeballing the axles, the 8 and 9 inch look very similar. The 9 inch requires a wrench to get the bottom nut off the studs holding the third member in. The 8 inch studs are all accessible with a ratchet and socket.
There is a 3.90 ratio out there from the factory also. I would not hesitate to scarf it up. I am thinking whole rear axles are about $100, so if you can find the right yard, the cost will be considerable less than you think. One small dilemma, you might encounter, the filler plugs were sometimes on the 3rd member, sometimes on the axle. You can fill the axle on the end of the axle housing, but you have to know the capacity. I have enjoyed relating swapping the gears. I hope you can find some good gears out there and enjoy the swap(s). If you are pulling parts from a whole car, pull the speedo cable from the trans and get the speedo gear, 7/16 wrench and screw driver will do the job. Good luck, let us hear about any progress.

 

[RPM]

If you want to change the rear end, and get exacly what you want, Speedway has center sections ready to bolt in.

A very quick way to go http://www.speedwaymotors.com/Ford-9-Inch-Posi-Traction-Third-Member-Assembly,6788.html

 

[railroad]

And that price is for a limited slip, so an open one should cost less.