Hey all I was wondering if I wanted to put some different heads on my stock 77' 302 say from another year of mustang or style of car what would be a good year to get the heads off of in hoping to gain some decent hp. Because I don't think I could justify putting down 1,200 for a new set of heads. Also can you use heads off of 351. I know some people have done it and I was curious to learn more. Also a net figure of how much hp would help. I was also wondering whats the best size of rockers to get get and what would the hp gains on that be. One last question, I was wondering how much hp can these cars handle before they start to twist what would be the max, before it would become risky. thanks
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Blue Thunder
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All heads in the 289/302 family have the same flow rates, even the elusive 289 "hi-po" are similar to the rest - 1.78" intake valves/1.46" exhaust valves. (In other words, their flow characteristics suck)admaster99 said:
1969-1974 351W heads have slightly larger intake ports and 1.84" intake valves/1.54" exhaust valves, so they flow quite a bit better than the 302 heads. 1975+ 351W heads are identical to the 302 heads, valves and all, but the combustion chambers are generally larger, so it will drop compression ratio on certain 302s, (namely, the pre-smog era high-compression small blocks)
If you want to use a set of '69-'74 351W heads, make sure to have a machine shop at least remove the big bumps in the exhaust ports to improve exhaust flow. You will need some hardened 7/16" washers for use on the head bolts, also, since the stock 302 block uses 7/16" head bolts and the 351W heads have 1/2" head bolt holes. (Or you could do what I did, and drill/tap the block for 1/2" bolts, which increases the clamping force on the heads.
In all honestly, if you're not looking to spend a lot of moola shmoola, raising the compression ratio is a more effective way of increasing power(and fuel economy, as well) than trying to get more flow from a factory small block head.
So just find a set of older pre-smog heads with the small "closed" combustion chambers, and bolt those on your '77 302. Just make sure you measure the chambers CC and do the math first, so you don't go too high on compression, or running pump gas will be out of the question. 10:1 is about as high as you can go on premium gas with iron heads. The '77 302 has about 8:1, so raising it by 2 points will give you a lot more torque, hp and throttle response.
As a side benefit, since higher compression raises engine efficiency, you will also see an increase in gas mileage. (and an increase in emissions, too. heh)
admaster99 said:
My 332" is making something like 500-530 hp, and 400-420ft/lbs at the flexplate, and I never run slicks, because something bad would definitely happen if I did.
I have no connectors or any other support in my coupe. It's showing signs of stress, such as small cracks on the quarters and on the window pillars, and the windshield keeps coming unglued across the top. My advice, don't go as high as I did without increasing rigidity in the body. hah.
You can get some used aluminum heads for under $1000. Or, get some E7's and send them to this guy:admaster99 said:
www.thumperoforangepark.com
Blue Thunder
Active Member
1badII said:
The GT-40s are very similar to the '69-'74 351W heads, same valves and all.
There is a story behind those E7 heads you mentioned. Ford tried out their new, state of the art "high swirl" small port heads in 1986 for their 302 HO, and they sucked ass beyond belief. Since they were confident of the new castings, they discarded the old original car 302 head molds from the 1960s. Later that year, Ford discovered the error of their way, and oops.. the old head molds were gone. So they turned to the truck division for heads, and thus, all "E7" heads are actually 302 truck heads. (That part number is "E7T", meaning 1987-truck casting)
Those heads have the same size ports and same puny 1.78"x1.46" valves as the early heads, there isnt any flow difference that I know of. Although the E7T ARE drilled for the smog holes, which means if you plan on porting the exhaust side, you need to press a 1/2"dia. long steel rod completely into the head, to fill that big smog hole. After which you can remove the bumps in the ports, and go about your porting business.
Blue Thunder
Active Member
admaster99 said:
GT40P heads are supposed to be decent for the street, but I've never examined a set of them in person. I think they come stock on the 302 explorers and mountaineers.
These things are dirt cheap:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7977380263&category=33617
Blue Thunder
Active Member
haha. I found a set of stock 1985 HO 302 heads for sale on ebay, too.
"Up for bidding is a very rare set of heads from a 1985 Ford Mustang HO 302. The engine was freshly rebuilt and dropped a piston. Heads survived in great usable condition. These two heads are what made the HO engine come alive"
These two heads are what made the HO come alive! hahaha!! (those same heads also made that old 1964 2 barrel 260 falcon station wagon come alive!)
"Up for bidding is a very rare set of heads from a 1985 Ford Mustang HO 302. The engine was freshly rebuilt and dropped a piston. Heads survived in great usable condition. These two heads are what made the HO engine come alive"
These two heads are what made the HO come alive! hahaha!! (those same heads also made that old 1964 2 barrel 260 falcon station wagon come alive!)
Blue Thunder
Active Member
thanks for all the help I really appreciate you guys are great, I guess for me right know the most appealing would have to be getting heads from www.thumperoforangepark.com because it sounds like a great deal and perfect for my application thanks again
Blue Thunder
Active Member
Eos said:Isn't the roller cam what made the engines come alive.I am pretty sure not having a roller block costed me a few ponies out of my 5.0
I would say, definitely, yes. Hydraulic cams are impossible to beat for street service. (solid rollers are even better, but arent all that reliable for daily street use, since the valve lash tends to beat up the rollers, and the roller lifters arent as durable in that aspect as a solid flat tappet piece) Roller cams open and close the valves much quicker than flat tappets, which means more "area under the curve" - the cam does more work in the same amount of time - the cam makes more horsepower, even when specs appear to be identical to a flat tappet's specs. They also last forever, and they free up even more hp than a flat tappet through reduced parasitic loses. Because there's no metal on metal contact with the cam lobes, there's less debris in the engine oil, which makes the engine itself last much longer. And lastly, because the roller cam is easier to turn, even the timing chain lasts longer as well, and the engine spins up quicker. That's why well maintained '85 and up HO 302s commonly run 200,000 miles and more. (my '85 had 150k when I sold it, and it still ran great, with no major engine work ever done)
I'm going to be switching to a hydraulic roller in my new motor, without a doubt.
Blue Thunder
Active Member
Eos said:
Oh yeah, there are "retro-fit" roller cams being sold, which supposedly allow you to run stock Ford roller lifters and spiders in the early non-roller blocks, because the retrofit camshafts have a smaller base circle, which places the lifters lower in the lifter bores. (the non-roller blocks like yours and mine have much shorter lifter bores than the newer roller blocks, so with a standard roller cam in an early engine, the lifters will stick way up out of the bores) I'm currently investigating the retro-fit cams, to learn about any possible problems.
Blue Thunder
Active Member
1badII said:
The 351W roller block I'm getting will have all the stock cam equipment in it, and I have a 302 roller block with everything in it, too. All I would need is the retro cam, which is something like $300, and a set of hardened pushrods. They offer only 3 retro grinds at CHP, but of the three, one fits my needs nicely.
Edit: if that sentence doesnt seem to make any sense whatsoever, it's because it doesnt make any sense whatsoever. That's what I get for typing when dead tired and low on blood-sugar.
What I meant to say was, the stock roller equipment is easy to find at junkyards, (I got the 302 roller motor for free, because it burnt a piston) So if you want to use the retro-fit cam, it's probably a lot cheaper to scrounge used roller parts than the aftermarket setup.
In my case, I'm (hopefully) going to be getting a 351W roller block, which eliminates the problem altogether, since then I'll just be buying a standard roller camshaft. (which, as you pointed out, has a greater selection of cams)
If the 351W roller motor deal falls through, I'll be ordering that retro cam, though!
jeffnoel
Founding Member
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