I think what PaulS was implying is that there are some Boss 302 cars out there that have lost their motors along the way. And yes, Boss 302 heads were complete overkill.
Yes. The heads were fitted with screw in studs and guide plates, unlike most Clevelands. The water passages were slightly moved as well. Yes to both. The engine was stout, but it had no bottom end power. That didn't matter. The only reason the car was built for public sale was that TransAm circuit rules at the time said that a car/engine combo could not be raced unless they were sold to the public in an acceptable quantity. 500 or more units if memory serves. Ford wanted to win TransAm because it had been dominated by Chevy for a while. For the street, yes. They whooped @ss against Chevy in 70! You will gain some depending on the head you choose. The head choice also will affect if you lose or gain at a given rpm. The best 2 reasons to go aluminum: 1) You can run an additional point of compression on the same fuel. If you run 87 octane now (example) with your stated 9:1, you can bump compression to 10:1 and have the same fuel requirements. 2) Weight loss. Every 100 lbs lost, is like adding 10 rwhp, or a tenth in the quarter. My Z28 was 3600 lbs and dynoed 318 rwhp. 0-60 was less than 5 seconds and a quarter was upper 12s. To make my 72 Mav just as fast, I should be able to do it with 218 rwhp because it weighs 2600 lbs right now. There is a certain amount of theory here, but it is pretty solid.
I cant get another engine block. The 302 will have to do. How much hp do you think you have. I didn't think the GT40 flow as much cfm's as alumn. aftermarket heads. What is the crank & stroke sizes for 302's. Can I just replace the crank? Maybe I need a bigger cam? I already have a 2500 stall though. I don't want to get another one.
what i was saying is that putting 351w heads on a 302w DOES NOT MAKE IT A BOSS 302! just wanted to clarify that. i would have to agree with 411, if your gears arent right you may not be letting what you already have see its potential. i would also have someone good with racing fords take a look at it and see if you can dial what you have in. a lot of people will tell you to throw more parts at an engine before you see what you have can do. if you still want more when you have yours dialed, then research what part is holding you back or what would work better how you drive it.
Where is it that you miss your power? What rpm, or driving situation do you want to improve? That is what you should be asking. Also, you can have a head that flows like crazy, but doesn't have any flow effieciency at the rpm you want to improve. It's a balancing act and the numbers can be confusing if the manufacturer puts out big flow numbers, but the port shape is not good. Dave
Trivia: What engine was the fore-father of the Boss 302? Hints: It was raced in TransAm in the mid 60s, but none were ever sold to the public in a car. The parts to build it were available over the parts counter for a short time though. Winner gets: Nothing!
hey ratio, what do you think of the trickflow TW chambers and ports. not trying to steal the post here just a somewhat related question.
I don't have any hands on experience with SBF aluminum heads, but I have heard that those are good ones. AFRs are my personal favorites for a larger engine. GT40Xs are my favs for a small engine. Again, I have yet to run some myself, but I have been researching them. They aren't too hard to run through a computer dyno program either... you just need a LOT of numbers and info on the heads to do it right. Dave
Those Gurney heads were just crazy... They came in so many different combos. 2 valves, 3 valves, 4 valves. They had standard configured ports with the intake over the lifter valley/exhaust out the sides OR reversed. Intake in the sides and exhaust out over the lifter valley. They usually had Weber or mechanical injection, but they even made some funky lookin' dual plane single 4v intakes for them. You don't see them for sale much, but when you do, it's a small fortune from the ones I have seen.
streetrod, you generated a lot of repsonses! That's good! As stated the boss 302 had very large runner cleveland closed chamber heads. To make a streetable boss you are better off using the 2V cleveland heads and creating what is sometimes called a clevor. These heads have smaller higher velocity runners that are more street friendly. Several problems arise when performing this modification. Virtually all of the US built 2v cleveland heads have the huge (read swimming pool size) 76cc combustion chamber. Drop these on a stock 302 and you need an 8-71 roots type blower to fill the chambers. Two ways to cure this problem. Buy a set of Australian 2V cleveland heads that have the 60cc combustion chamber or find a set of ford SVO 2V cleveland heads. Almost forgot that aluminum cleveland heads are now available. You can modify the water passages to fit the 302W or 351W block. However, you still have the problem of piston to valve clearance. You can only run a max of about .470 lift using these heads unless you have boss type pistons specific for the canted valve heads. I assume you have the stock inline valve reliefs which would limit your cam choice. You can buy hypereutectic pistons with cleveland style valve reliefs and 302 (not boss 302 or 289) compression height. This will allow you to use these pistons with stock 302 length rods. Also, you can buy intake manifold adapters that allow you to bolt standard 302 intakes to the cleveland heads. It certainly is true that a good set of AFRs or edelbrock heads would flow better and likely cost less in the end. But, a boss 302 or clevor has a certain amount of cool factor. Go to this website and look at the flow numbers. The stock GT40s flow almost as well as the stock 2V clevelands. http://www.jason.fletcher.net/tech/flowdata/cleveland.htm Good luck with whatever choice you make! BTW, in the near future I may have some clevor pistons, 2V heads and intake adapters for sale. I haven't decided if I will go the road less traveled and build the clevor. Would be the only maverick with an injected clevor! Again, a certain amount of cool factor with the boss! I even have a set of grabber body stripes for the car that say 302 boss instead of grabber! Bet some would ask if that was a factory option in a maverick!
