Hello,
I have a 1984 Ford Bronco XLT with a 1967 289 with 78 302 Heads, 302 2 Barrel Intake, 2 Barrel Carb, 3 Speed Manual Transmission with OD (4th Gear).

I just bought this Bronco from a friend, the engine is practically brand new. (Less than 3000 miles on the engine) The problem is this. He wanted to have good gas mileage when he built the engine, but I think he over did it. He had a NAPA Economy Cam installed, and put on a 2 BRL Carb. I have a factory 4 BRL 302 Cast iron intake, and a Holley 600 CFM 4 BRL Carb for the truck. Now here is the thing. This 1967 vintage 289 engine when it was rebuilt was bored 30 over, and had flat top pistons installed. Also of note is there is an electronic distributor out of a 78 302 installed in this engine. I want to put a more agressive cam in the engine and install the 4 BRL intake and Carb. The problem is with the engine being peiced together as it has been what Cam do I need? I mean intake and exhaust duration? The engine runs very good but has no power whatsoever on the top end. Low End is fairly good, not impressive but decent. I want to get this thing going a little without killing drivability. I was thinking about going toward a stock grind cam for a 289 4 BRL, but with the 78 302 Heads and the Flat Top pistons I just dont know. What grinds can I use with out throwing the valves into the pistons? Any help you guys could give would be appreciated.

THANKS!!!

 

i would sell this motor and get a 351w. it will give you the things you are looking for and be reliable. if you start to try to mix parts , you will spend probably more than you would if you find a low or mid mileage 351w.
the older 289/302's, were not real torquey.
the other thing to check before doing anything is to see if you are getting any spark advance.
the ignition systems from 78 to 84 are different and use different spark advance methods, so you might not be getting optimum high end performance.
good luck and do your homework before you spend your dough!!

 

Changing motors is not an option. I realize the 351W is a good motor. But in my opinion the 289 is the best Small Block ever built by Ford. The problem is the guy didn't build it for performance, he built it for economy. I need to remedy that. I don't need to replace a perfectly good (brand new) motor. Thanks anyway.

 

A good "RV" cam.. something in the area of 214/218 lift, 470/480 lift.. lots of manufacturers make good torquey cams... should work for what you want... I am running a sligthly longer duration/lift (224/228, 476/498) but it is in a 351W.... but it dont quit pulling untill I chicken out and back off... and the gas milage sucks big time... but then again that is how I had the engine built...

Those '78 302 heads hurt you on the top end.. small valves and poor flow characteristics.. you are deep into the emmission heads by that year... so no matter what you do with a cam and intake changes you are not gonna get much out of the top end..

hope this helps....

Bill in Mobile
'64 F100 Shortbox ('70 351W/'76 C4)

 

Bill, Yeah your right about that. The guy I bought the truck from has 289 HiPo heads. Problem is he said if I stick those on its gonna send the compression through the roof and I would have to goto the airport for fuel. Ugghhh, This sucks.

 

> Bill, Yeah your right
>about that. The guy I
>bought the truck from has
>289 HiPo heads. Problem is
>he said if I stick
>those on its gonna send
>the compression through the roof
>and I would have to
>goto the airport for fuel.
>Ugghhh, This sucks.


Maybe not! I say, if the HIPO heads are in good shape, it will only cost you a "valve grind" gasket kit to find out if they are acceptable. Also, an RV cam, as already suggested, might allow you to advance the timing enough to eliminate spark knock. I would try them, that motor should really run with those heads!

Nathan

 

The Heads have been reconditioned, but he decided against using them. I might just try it out. I dunno. I did take the truck to my mechanic today, he found that the distributor was 2 teeth off. He said the timing was retarded big time. So he fixed that and readjusted the carburator. He said my diapragm might need replaced as well. He doesn't think its advancing the timing with acceleration. It is running ALOT better now. I think with a 4 BRL and a good Intake and a little more agreesive Cam to compensate for the rather large Heads I should be okay. I'll be doing that in a few weeks. I gotta get this stuff figured out before I put the lift kit and 32's on it You know? It doesn't have enough b@11s to turn that big of tires right now. LOL

 

Have you thought about regearing your bronco? A 4.10 or 4.56 set will make a difference.


Pastmaster's 1993 XLT 5.0 E40d 3.55LS Normal Cab/Long bed Loaded from the factory with aid of...MSd 6a ign/s.p. wires, blaster coil, Hypertech Chip, K&N filtercharger, Cat-back dual exhuast w/o mufflers, 3.5", echo tips, Accel distributor cap, Dark Mocha over light mocha. 5% Dark tint, Alpine Cd player/remote, Pioneer speakers.

 

No I haven't really thought about regearing. How much would that cost? Where can I buy gears? I don't even know what type of axles are in there. Ford 9 in the back? Dana 40 up front? Can U get the gear set from the dealer?

 

>No I haven't really thought about
>regearing. How much would that
>cost?

A professional job w/o any lockers could be around $500-$600. Unless you want to attempt it yourself or know someone who'll help you.

Where can I buy
>gears?

(www.summitracing.com) has gear sets at $195.

I don't even know
>what type of axles are
>in there. Ford 9 in
>the back? Dana 40 up
>front?

Probably it has a Dana 44 IFS up front and a Ford 8.8. in the rear. Check your door code for a number and someone on here will tell you what it is.




Can U get the
>gear set from the dealer?
>

Yes, probably but that would be mighty expensive.






Pastmaster's 1993 XLT 5.0 E40d 3.55LS Normal Cab/Long bed Loaded from the factory with aid of...MSd 6a ign/s.p. wires, blaster coil, Hypertech Chip, K&N filtercharger, Cat-back dual exhuast w/o mufflers, 3.5", echo tips, Accel distributor cap, Dark Mocha over light mocha. 5% Dark tint, Alpine Cd player/remote, Pioneer speakers.

 

 

papaul, it sounds to me as if you want to have a powerful truck. the easiest and most reliable way to get this is with cubicinches.
i still think you should ditch the 289/302 motor you have and go with 351 or460!!!.
the 351 will cost the least in additional parts to get it to fit , but the 460 will pull like you can't imagine.
if you start changing rears, the rpm range changes and you get more power to the ground, but you have to spend bucks to do it.
i am glad you checked the timing as i suggested in my first reply,not having spark advance can really affect power.
just curious, why is getting rid of 289 not an option?