How much power is a 289 worthy of?

[ZStanger]

Well, I found a 1968 Mustang and absolutely fell in love. (Not that I can get it or anything, its $8875, But still don't have that kind of money) Its fresh repainted Gulfstream Aqua w/ a White C-Stripe. It has a 289/C4 combo. A J-Code Intake and Holley 600 Carb would be included. The motor is stock, But I was thinking. I see many affordable Mustangs w/ 289's on the net. Is this a good powerplant for some power? Not extreme, let's say over 300 HP. I would like 325-350, Is that farfetched? I would just like some pick-up when I step on it. So my question is, Is the 289 a decent powerplant to make a little horsepower?

Thanks, I figured i could get a little bit more input in here.

BTW - I'm talking reasonable mods. Cam, Intake, Carb, Headers, Heads, etc. No Superchargers, Boring, Stroking (I'll think about those later), Engine Swaps, Crates, etc. Reasonable Do-It-Yourself mods that can be done out in the driveway. I realize there was a High performance 289, w/ 271 HP, but this one has the base 4-bbl. 289 (225 HP) Also, No Nitrous. Im not a big fan.

 

[rbohm]

300-325 hp from a 289 is not hard to do. performer rpm or weiand stealth intake, comp cams xe274h cam, tri-y headers, 525 road demon carb, and a set of windsor jr or afr 165 heads, and you should be very close.

 

[jcp123]

my car is a cam away from 300hp. i ported my stock heads, put on roller rockers, an edelbrock performer rpm intake and edelbrock 600 carb, and got the compression to 9.5. i have electronic ignition and tri-y headers. i looked at a relatively mild cam that according to desktop dyno would yield me about 310hp. if you did as i did to mine, one step up from that is all you'd need to make that kind of power from a 289. not hard at all

 

[none67]

a 289 can make almost as much power as a 302(around -5,-10hp at 350hp) but becuase of its really low stroke it can out rev a LOT of motors out there. its my small block motor of choise with out a doubt.

325ish hp is nothing really (at the fly wheel) stock heads can do it if you have a good intake, cam, carb(s), headers, and an elec. fan. mind you it must be tuned perfect so it will a little less.

 

[GaPonyFarm]

So my question is, Is the 289 a decent powerplant to make a little horsepower?

You can easily get the 289 to 400 hp, at the crank, without any extreme measures. If you decide to go for more, I'd recommend getting a good 302 block and build it up from scratch...machine the block, 347 stroker kit with forged crank, forged pistons, manley rods, etc.

300 hp will be a piece of cake with a few bolt-ons. Eliminating loss through the drivetrain will be your biggest challenge.

 

[Big Chuck]

i am currently in the beginning stages of rebuilding my 65 289. by beginning, i mean havent started yet. im on a budget, and am having trouble deciding what to do about heads. would it be a better idea(power to money ratio) to port out my stock heads, or find some pre-emission (70's) 351w heads to just rebuild. which would flow better?

 

[ZStanger]

Eliminating loss through the drivetrain will be your biggest challenge.

Would a Tremec TKO and 3.55's Help at all?

 

[usedtobe 67p51d]

new heads are almost cheap when you add up valves,seats,guides & labor. as for horsepower I have 343 rwhp and it's not enough! but it's not easy to drive around town, poor idle on/off power, doesn't like to go slow Jim

 

[60sStang]

i am currently in the beginning stages of rebuilding my 65 289. by beginning, i mean havent started yet. im on a budget, and am having trouble deciding what to do about heads. would it be a better idea(power to money ratio) to port out my stock heads, or find some pre-emission (70's) 351w heads to just rebuild. which would flow better?

If you already have an air compressor I would say to port the 289 heads. I bought a die grinder on ebay for $15 and the porting kit from summit for $35 and am porting my heads right now. Check out the forums at formuscle.com ... there are plenty of pictures of what to do and how to do it. It takes time to port them though, so if you are tight on time it might not be your best option.

 

[jesserose17]

Would a Tremec TKO and 3.55's Help at all?

Yes - using manual transmission is the best efficient way to reduce drivetrain loss.

 

[dolfan87]

Would a Tremec TKO and 3.55's Help at all?

The TKO is a bit overkill for a 325 hp 289. You could use a 3550, or even a stock T-5 if you "be nice" to it.

I am running a 500hp 393, and I was still considering the 3550 when I finally decided on the TKO.

87

 

[geegee]

Several factors play into how a car performs; horsepower is only one of the factors. Others are horsepower to weight ratio; gearing, etc. Old cars with horsepower to weight ratios of 10:1 or greater start feeling pretty perky. Torque gets you going; so having lower gear ratio provides for quicker starts. Example: for the same horsepower going from 3.00 to 3.50 gears is a real kick in the pants. You can only take this idea so far else your gas mileage goes to pot in addition to the car feeling like its a dump truck! Hence, a good compromise for old street driven Mustangs are 250-300 hp, 3:50 gears and a 5 speed transmission.

 

[Edbert]

new heads are almost cheap when you add up valves,seats,guides & labor. as for horsepower I have 343 rwhp and it's not enough! but it's not easy to drive around town, poor idle on/off power, doesn't like to go slow Jim

343 at the wheels from 289ci (or 294)? NA without PA?

 

[jesserose17]

How about those GT40 heads? How would they compare with 351W heads? Don't 351W heads require some modifications for 289/302 block?

 

[66'Stanger]

This is very interesting to me. I would really like to get more power out of my car. I'm getting a new 302 put in it. What would I need to do to get about 350-400hp out of my motor? So far I've only gotten a 625 cfm Road Demon carb and a Edelbrock performer intake. How much would a 347 stroker kit give me?

 

[jesserose17]

351w heads (early ones) were GT40 heads. The chamber on '69 - '70 351w heads were known as the GT40 design. No mods required to use the heads on a 289/302. Need to use 289/302 head gaskets and 351w intake gaskets (Felpro 1250s or 1262s work). Some people drill the steam holes in the 351w heads, but it's not a necessity.

I think 351W heads have 1/2" bolt holes, so I assume one would need to use sleeves for 289/302 bolts, right?

 

[65 fastback]

Originally Posted by jesserose17
I think 351W heads have 1/2" bolt holes, so I assume one would need to use sleeves for 289/302 bolts, right?

ARP makes tapered head bolts for this conversion.

Tim

 

[jesserose17]

Cool - thanks for the info about the 351W heads.

 

[sixtyfive]

ported 289 heads ran slightly better then the 351's my car has now with my setup,
ended up putting a hole into the waterjacket with the 289 heads and the difference was so little im just stayin with the 351's

289's and 302's are both great for torque

 

[Ro Jo]

Respectfully disagree with power numbers

You can easily get the 289 to 400 hp, at the crank, without any extreme measures...

300 hp will be a piece of cake with a few bolt-ons. Eliminating loss through the drivetrain will be your biggest challenge.

It certainly depends on your definition of "easily" and "piece of cake" but according to my research and experience, getting more than 1HP per cubic inch is difficult and costly. The cost for each additional HP gain over 1 per increases dramatically.

I'm not saying it can't be done, in fact some people are running around with 289s having much higher HP numbers...the issue is streetability and reliability (also open to interpretation). In order to get any real power out of the 289 you have to wind the crap out of it (6,000-8,000 rpm) which gets really old after a while and the 289 is famous for its lack of low-end torque which is what you use most on a daily driver.

Someone around here has a very appropriate quote - I'm too lazy to find it but it goes something like this: Fast, Cheap, or Reliable; you can have 2 out of 3, take your pick.