302 engine upgrades

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

big_burgey

Member
Joined
Jan 7, 2015
Messages
10
Reaction score
0
Location
Gatesville texas
My Car
1972 mustang 302
Hello everyone I have a 1972 mustang coupe with a 302 2bbl I'm wanting to give it a little more power for street use I'm going to be switching out the intake and carb for a four bbl set up I'm looking for any advice on cam, lifters, rockers, timing, ign set up to add hp with out changing the heads. Any suggestions

 
The most loaded and controversial small block Ford question ever :)

Unfortunately, changing the heads is the shortest route to more street power in a 302.

Unported, used GT40 iron heads by themselves should give an easy 30hp over the stockers while keeping everything else the same.

Otherwise, a mild cam change and headers are the next things I'd change.

Intake would be next.

The rest would depend on the depth of your wallet.

All in my opinion, of course.

 
Last edited by a moderator:
I appreciate the info my buddy told me to just get a roller 302 and build up from there which is what I'm going to do in the future but for now I'm just wanting a little more play power until I'm done restoring it I think my issue is ratios I found some stuff on ebay but I don't wanna mess anything up by putting the wrong parts in it


So if I go with a mid cam the stock push rods lifters and rockers will fit?

 
Last edited by a moderator:
if you install any cam bigger than stock, you should install screw in rocker studs and stiffer valve springs otherwise the studs will likely pull up and the valves will float.

the easiest way to increase the rate of acceleration is to install numerically higher gears.

 
Last edited by a moderator:
Is your engine in good shape?

I agree with the gears suggestion, going from 2.75's which your car likely has to a 3.50 or so will make the car feel like it gained 50hp!

After that gets old, headers, exhaust and an intake and carb swap...

 
The motors in good shape and call me dumb but u mean the gears in the diff?


Yeah I'm going to rebuild the 9 inch I'll go with a 3.50 ring and I was told I should me fine with an rv cam

 
Last edited by a moderator:
The motors in good shape and call me dumb but u mean the gears in the diff?
the gears in the rear end...in the axle housing.
with 350 gears and an "rv" cam your engine won't want to run 70 mph on the freeway very easily but if you just drive around town then its fine . . you might consider 3.40 gears also.

I was told I should me fine with an rv cam
i suppose the person that told you that also said he would pay to fix your engine if it breaks then.

if you install any cam bigger than stock, you should install screw in rocker studs and stiffer valve springs otherwise the studs will likely pull up and the valves will float.
 
Last edited by a moderator:
Are you going to at least do some head work? Is that a plan for the future? They certainly are your weak link. If you had a decent set of heads, I would say an Edelbrock Air gap intake (definitely streetable and good enough to work with a stroker setup if you wanted), camshaft I would look at 218/226 & .050" on a 112' LSA and a nice set of headers with and X-pipe. For your carb, I'm thinking 500-550 cfm. The first thing I would do is a set of 3.25 or 3.50 gears. Considering the power it takes to turn a 9" rear, I would actually consider an 8.8 rear end from a newer mustang. It will hold any amount of power a 302 with bad flowing heads will make.

 
It's always a lot of fun, planning a restoration, or a resto mod...My free advice, is have an overall goal for the car. Is it going to be a daily driver, or a weekend cruiser? Is it EVER going to see any race track, or just street performance? You can get a lot of stuff used on the local craigslist, but it gets very expensive, doing things twice over...If you aren't concerned about low E.T., then a new carb, intake with headers and dual exhaust will for sure help. If you are going to build a monster motor later, and rebuild the suspension to accommodate 500 lb ft of torque and price is no object, then go ahead and gut the car, and start shopping for a 429/460..

Before you change the gears in the rear end (that is a very good way to make the car "quick" off the line), you need to think about your overall goals. It doesn't make sense to change the rear gear, to find out your new cam requires a higher minimum gear.

The cam and rear gears work together, in order to get all the value out of your build.

For example, my 289 is a .030/.010 over and under, with a performer RPM cam, .496/.520 lift. I have a T5 trans, and a 3.50 rear gear.

the engine makes good power, and pulls very nicely with the 3.50, but as soon as I go for the OD, the car lugs.....If I had at least a 3.73 or a 3.89, I could still be "on cam' in 5th gear, while still maintaining a lower cruising RPM....Think about what you want to do with the car realistically, and then plan accordingly.

 
Good point- you should have a plan of "what you want when you're done" it you could end up with a lot if mismatched parts. It's just that heads are the key to make any power. Even if you went with a set of factory 351w heads.

 
Thank you everyone for the info my goal is to restore the car with a little play power like quicker passing it's not going to be a race car I wanting a little more power so if I change my heads what would be a good option I hear gt40 are good and someone mentioned 351w heads and if I changed the heads will I need to change anything else?

 
Thank you everyone for the info my goal is to restore the car with a little play power like quicker passing it's not going to be a race car I wanting a little more power so if I change my heads what would be a good option I hear gt40 are good and someone mentioned 351w heads and if I changed the heads will I need to change anything else?
the gt40's are no big upgrade . . the gt40p's are far better . . the p's fit with most non tri y headers if you use the short moroso spark plugs and 90 degree ceramic boots but both need new springs with any performance cam . . you can buy eddy e street aluminum heads for only $950.00 . . if you use windsor heads you should port the bejesus out of the exhaust.

 
Last edited by a moderator:
The OEM 351W heads are just not worth the effort and cost VS aftermarket. The chambers are larger and require the use of bushings for the head bolts.

Chuck

 
I installed a new set of gt40p heads on a 302 I used to have few years ago and was only mildly impressed them, the gain wasn't worth the effort to me and I felt like some performance aluminum heads would have been a better choice but your results may vary:)

 
I installed a new set of gt40p heads on a 302 I used to have few years ago and was only mildly impressed them, the gain wasn't worth the effort to me and I felt like some performance aluminum heads would have been a better choice but your results may vary:)
the p's flow around 25% more than a stock early 289/302 head but the chambers are also larger than early heads . . if one does not mill the heads to increase the compression to around 9.5 then a lot of the benefit from the increased flow can be canceled by the reduction in compression.

 
Last edited by a moderator:
I should have mentioned that my old 302 was a 95 5.0

ho in a mustang gt that had E7 heads that I switched out to gt40p's. The car also had a cobra intake manifold, bbk shorty headers, offroad H pipe and alot of other goodies. The car ran good but my cleveland runs and sounds alot better.

Another 302 I had came with the dreaded variable venturi carburetor on it. I installed an edelbrock rpm intake, holley 600 vacuum secondary carb and a good dual exhuast system on it and that car picked up big alot from 3 fairly simple mods.

 
Hello everyone I have a 1972 mustang coupe with a 302 2bbl I'm wanting to give it a little more power for street use I'm going to be switching out the intake and carb for a four bbl set up I'm looking for any advice on cam, lifters, rockers, timing, ign set up to add hp with out changing the heads. Any suggestions
read this http://www.hotrod.com/articles/ford-302-v8-engine-buildup/d this

 
Back
Top