Need advice on upgrading 68 289

csunracer · 01-28-2003, 01:17 PM

Hey everybody, I have a '68 coupe that has an all original 289 with the factory 2barrel carb on it. I wanted to freshen up the motor and get a little more horsepower out of the car by changing some of the components. I have a friend who is selling a set of motorsport Gt-40P heads that are mildly ported, along with an edelbrock performer RPM intake manifold that is match ported to the heads. He is going to sell me both items for $440. My question is, what else should I consider changing? He also has a motorsport B303 cam, and a holley 750 doublepumper. Should i go for a cam and a carb? Or just a carb? Other items I am going to replace are the feul filter and the and the feul pump, and the exhaust. Any and all help would be greatly appreciated.

mustangII460 · 01-28-2003, 08:20 PM

Since you asked,

I would buy those parts from your friend and put them up. Then I would save my money to buy a 302 short block. Several different companies sell complete short blocks. Just tell tell them what heads/cam/compression you have or want to run.

750 double pumper, way too big.

If your on a budget as most of us are. Look for a used complete late model 5.0 motor.

The bigest bang for your buck would be some new rear end gears. Search the want adds for a 3.55/3.70 or about that. Simply change out the center section with the used one. Atleast this way while your saving for a motor, your rear end will be ready. You won't set any track records, but your car will have a lot more out of the hole, even with your two barrel.

Frank

csunracer · 01-28-2003, 08:29 PM

Well like I said earlier. All i want is a little more pep. I have a 91 5.0 Notchback that's fully dragged out and runs 11.90s so i'm not really looking for that type of performance. These heads, cam, intake and carb are coming off of another 91 LX and with that combo along with a stock 302 short block he ran 12.60's.... Assuming I did use these parts, and opted for 3.55 gears...what kind of performance should I expect to have?

mustangII460 · 01-29-2003, 05:45 PM

If you want a little more pep, do a tune up.

csunracer · 01-29-2003, 06:06 PM

Thanks for the lack of sarcasm in your help. Anyways, to anybody else who is willing to lend a helping hand. I negotiated a deal with a friend of mine to sell me his short block out of his 91 5.0 along with a set of ported Gt-40p heads, a match ported edelbrock performer RPM manifold. a motorsport b303 cam and the water pump for 630$. Would a holly 650 doublepumper be a good carb for this setup? What else should I consider replacing besides the feul pump and the gears out of the rear end?

lskarritt · 01-29-2003, 07:01 PM

if its a c4 trans go witk a 600 cfm vac sec,

mustangII460 · 01-29-2003, 07:37 PM

"Like I said earlier. All I want is a little more pep." To me that means a couple of simple things. IE: headers, new carb maybe gears.

Going from a stock 289 2v to GT40 heads/ cam /carb/ intake/ 3.55 gears/ short block. And the friend ran 12.60's with the parts. And you didn't want to run 11.90's like your drag car? Is more than a little pep 2 me.

Maybe I just see things different than most people, heck, wadda expect from a Disabled Veteran.

When I posted the , "Do a tune up" that was a atempt by me to be funny because of your contradictory statements. No biggy. We all live and learn. Everyone is unique in his or her own ways. The world would be boring as heck if we were all the same.

Sorry for any misuderstandings on my part.

Frank

lx mike · 01-30-2003, 04:05 PM

Get the heads,intake and then go get a vac secondary carb and go have fun. You'll need different headers with the heads. the plugs are angeled so check about that before you do get them.

Jeff65 · 01-30-2003, 05:33 PM

Sounds like you have a good start. The GT40P's perform well with good headers. The carb is a bit big for a street car. The calculation for a street car (idle-6000 rpm) is about 520 cfm so you should stick to a carb somewhere near this for best all around performance, 570 cfm, 600 cfm, okay. The 750 cfm would be great at wide open throttle using a single plane manifold and a good set of long tube headers, else it would be overkill.

The worst part of this mixture is GT40P heads are "Explorer" configuration and finding headers that fit and are cheap is a chore. A couple years ago, there were none. Today there are several manufacturers who make early Mustang headers that fit the P heads.

B303 is a fairly high hp grind used in the late model roller block engines. I don't believe this is suitable for a flat-tappet installation and even were it, the grind is a bit towards the high end. Again, fine with the single plane manifold and large carb but not so great for a street car (okay beat me up)! I would go with a mild street Comp Cam kit.

csunracer · 01-31-2003, 01:34 AM

Thank for the info Jeff. I talked to some friends, and I was directed to a set of long tube headers that Mac makes for this application. So i'm probably going to get a set of those. In regards to the cam I'm planning to switch over everything to a roller setup. Get a set of lifters and some crane 1.6 roller rockers and call it a day. My goal is to keep this car streetable but still retain the use of my AC. Havn't had a mustang with a working AC for about 7 years since I watched my 91 notchback go from a completely stock every day driver, to a stripped down beast that gathers way too much attention from the wrong places. BTW anybody in the market for a dragged out 91 notchback?

Jeff65 · 01-31-2003, 01:09 PM

My '65 is FRPP Motorsport 302 (5.0L HO roller) with E303 cam and GT40 heads. This is very much what you're building. It idles a bit lopey at 650 rpm (Holley Street Avenger, Weiand Stealth, Hooker headers). With T5 and 3:50 gears it provides a good combination of street/strip performance. It is not the fastest 302 around but no one laughs at it either. On the street it has that "muscle car" sound and demeanor. Has a surprizingly big block feel to it at the traffic light. I'm quite happy with it.

02-02-2003, 01:16 PM

You might consider waiting to put your new motor in and just going with some gears and a hard shift kit, or short throw shifter, i think that would give you a lot more aggressive feeling street car with out spending a lot of money, just my .02

steven

01-28-2003, 01:17 PM	#1
csunracer Registered Member Join Date: Jan 2003 Location: Chatsworth, CA Posts: 10	Need advice on upgrading 68 289 Hey everybody, I have a '68 coupe that has an all original 289 with the factory 2barrel carb on it. I wanted to freshen up the motor and get a little more horsepower out of the car by changing some of the components. I have a friend who is selling a set of motorsport Gt-40P heads that are mildly ported, along with an edelbrock performer RPM intake manifold that is match ported to the heads. He is going to sell me both items for $440. My question is, what else should I consider changing? He also has a motorsport B303 cam, and a holley 750 doublepumper. Should i go for a cam and a carb? Or just a carb? Other items I am going to replace are the feul filter and the and the feul pump, and the exhaust. Any and all help would be greatly appreciated.

01-28-2003, 08:20 PM	#2
mustangII460 Factoy Five Roadster Join Date: May 2000 Location: Sevier Co,Tennessee Posts: 1,681	Since you asked, I would buy those parts from your friend and put them up. Then I would save my money to buy a 302 short block. Several different companies sell complete short blocks. Just tell tell them what heads/cam/compression you have or want to run. 750 double pumper, way too big. If your on a budget as most of us are. Look for a used complete late model 5.0 motor. The bigest bang for your buck would be some new rear end gears. Search the want adds for a 3.55/3.70 or about that. Simply change out the center section with the used one. Atleast this way while your saving for a motor, your rear end will be ready. You won't set any track records, but your car will have a lot more out of the hole, even with your two barrel. Frank __________________ Frank

01-29-2003, 05:45 PM	#4
mustangII460 Factoy Five Roadster Join Date: May 2000 Location: Sevier Co,Tennessee Posts: 1,681	If you want a little more pep, do a tune up. __________________ Frank

01-29-2003, 07:37 PM	#7
mustangII460 Factoy Five Roadster Join Date: May 2000 Location: Sevier Co,Tennessee Posts: 1,681	"Like I said earlier. All I want is a little more pep." To me that means a couple of simple things. IE: headers, new carb maybe gears. Going from a stock 289 2v to GT40 heads/ cam /carb/ intake/ 3.55 gears/ short block. And the friend ran 12.60's with the parts. And you didn't want to run 11.90's like your drag car? Is more than a little pep 2 me. Maybe I just see things different than most people, heck, wadda expect from a Disabled Veteran. When I posted the , "Do a tune up" that was a atempt by me to be funny because of your contradictory statements. No biggy. We all live and learn. Everyone is unique in his or her own ways. The world would be boring as heck if we were all the same. Sorry for any misuderstandings on my part. Frank __________________ Frank

01-30-2003, 04:05 PM	#8
lx mike Undescribable Join Date: Sep 1998 Location: Ft Myers Fla Posts: 1,539	Get the heads,intake and then go get a vac secondary carb and go have fun. You'll need different headers with the heads. the plugs are angeled so check about that before you do get them. __________________ Rice Haters Club Member #101

01-28-2003, 08:29 PM	#3
csunracer Registered Member Join Date: Jan 2003 Location: Chatsworth, CA Posts: 10	Well like I said earlier. All i want is a little more pep. I have a 91 5.0 Notchback that's fully dragged out and runs 11.90s so i'm not really looking for that type of performance. These heads, cam, intake and carb are coming off of another 91 LX and with that combo along with a stock 302 short block he ran 12.60's.... Assuming I did use these parts, and opted for 3.55 gears...what kind of performance should I expect to have?

01-29-2003, 06:06 PM	#5
csunracer Registered Member Join Date: Jan 2003 Location: Chatsworth, CA Posts: 10	Thanks for the lack of sarcasm in your help. Anyways, to anybody else who is willing to lend a helping hand. I negotiated a deal with a friend of mine to sell me his short block out of his 91 5.0 along with a set of ported Gt-40p heads, a match ported edelbrock performer RPM manifold. a motorsport b303 cam and the water pump for 630$. Would a holly 650 doublepumper be a good carb for this setup? What else should I consider replacing besides the feul pump and the gears out of the rear end?

01-29-2003, 07:01 PM	#6
lskarritt Registered Member Join Date: Dec 2002 Location: commerce mi Posts: 8	if its a c4 trans go witk a 600 cfm vac sec,

01-30-2003, 05:33 PM	#9
Jeff65 Registered Member Join Date: Jul 2002 Location: Oklahoma City Posts: 208	Sounds like you have a good start. The GT40P's perform well with good headers. The carb is a bit big for a street car. The calculation for a street car (idle-6000 rpm) is about 520 cfm so you should stick to a carb somewhere near this for best all around performance, 570 cfm, 600 cfm, okay. The 750 cfm would be great at wide open throttle using a single plane manifold and a good set of long tube headers, else it would be overkill. The worst part of this mixture is GT40P heads are "Explorer" configuration and finding headers that fit and are cheap is a chore. A couple years ago, there were none. Today there are several manufacturers who make early Mustang headers that fit the P heads. B303 is a fairly high hp grind used in the late model roller block engines. I don't believe this is suitable for a flat-tappet installation and even were it, the grind is a bit towards the high end. Again, fine with the single plane manifold and large carb but not so great for a street car (okay beat me up)! I would go with a mild street Comp Cam kit.

01-31-2003, 01:34 AM	#10
csunracer Registered Member Join Date: Jan 2003 Location: Chatsworth, CA Posts: 10	Thank for the info Jeff. I talked to some friends, and I was directed to a set of long tube headers that Mac makes for this application. So i'm probably going to get a set of those. In regards to the cam I'm planning to switch over everything to a roller setup. Get a set of lifters and some crane 1.6 roller rockers and call it a day. My goal is to keep this car streetable but still retain the use of my AC. Havn't had a mustang with a working AC for about 7 years since I watched my 91 notchback go from a completely stock every day driver, to a stripped down beast that gathers way too much attention from the wrong places. BTW anybody in the market for a dragged out 91 notchback?

01-31-2003, 01:09 PM	#11
Jeff65 Registered Member Join Date: Jul 2002 Location: Oklahoma City Posts: 208	My '65 is FRPP Motorsport 302 (5.0L HO roller) with E303 cam and GT40 heads. This is very much what you're building. It idles a bit lopey at 650 rpm (Holley Street Avenger, Weiand Stealth, Hooker headers). With T5 and 3:50 gears it provides a good combination of street/strip performance. It is not the fastest 302 around but no one laughs at it either. On the street it has that "muscle car" sound and demeanor. Has a surprizingly big block feel to it at the traffic light. I'm quite happy with it.

02-02-2003, 01:16 PM	#12
Young_Pony Guest Posts: n/a	You might consider waiting to put your new motor in and just going with some gears and a hard shift kit, or short throw shifter, i think that would give you a lot more aggressive feeling street car with out spending a lot of money, just my .02 steven

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