This forums has to be as good as sitting down with any of the Ford engine builders in the 60's. I have got some much to learn about Ford cars. Thanks I guess by Thanksgiving I will make a good choice.
Introduced to the Boss Mustang line in 1972 was the Cleveland 351, It was installed in favor of the 302 which was used in 1971 after the Boss 302 had been dropped from the lineup after 1970. In 1970 the HP engines used in the Boss Mustangs were the Boss 302 and the Boss 429. After 1970 the Boss 302's dissapeared except for those that were held in reserve by racing houses, some of which were released to the public as rules changed for the racing associations. If you pull a 302 out of a 1971 Mustang the chances of getting a Boss 302 are about 1 in 3. There were some that were produced early and got the 1970 engines. The same thing happened with the four barrel 351 Windsor from 1969 - Some of the 1970 cars got the older moter but it is not common. The fact is that if you get a 302 from a Boss Mustang after 1970 it is not likely to be a Boss 302. How to identify the Boss 302: #2, #3 and #4 mains are 4 bolt The soft plugs in the sides of the block are iron screw-in plugs The heads have large oval ports on both the intake and exhaust The blocks had cutouts in the top of the bore for valve clearance and at the bottom for clearance rod big ends and counter weights. There was a baffle in the pan and a windage tray that bolted to the three center four bolt main caps. The screw-in studs in the heads retained guid plates. Ford did not put 351 Cleveland heads on any 302 - it wasn't until after the after maket folks had made the exchange possible that Ford came up with the head mods and the special intake required for the swap. The first swaps used the heards , spacer plates for the intake and special water manifold adapter. Machining was absolutely necessary before Fore ever jumped on the band wagon with this swap. Ford Motor Sports now has after market heads that make the swap easy. PaulS
There were no Boss Mustangs in 1972. The 351 Cleveland was introduced to the Mustang lineup in 1970. The 1969 Mustangs were offered with the 351-4v Windsor. In 1971 the only Boss Mustang produced was the Boss 351. There are a couple of rumored Boss 302 cars in 1971. There were no Boss Mustangs built after 1971 with the exception of the graphics only fox based Mustangs of the late 90's.
You are right about the introduction of the 351 Cleveland - That was a typographical error... "... in mid-1969 the Boss 302 was born. with a base price of $3720, it was no kiddy car, but the looks, handling and performace were there. Although the 302 powerplant was the same basic block as the regular model, everything else was designed for durability and high RPM's. Standard equipment included a forged steel crank and rods, 10.6 to 1 pistons, free flowing heads with canted valves, 780 cfm Holley on aluminum high-rise manifold, dual point ignition and hot solid lifter valve train." An exerpt from "Mustang - breeding improves the race" an article in "The Complete Book of Fords" by Peterson publishing. The 302 mods for the Boss engine also included beefier rods with oval head 3/8 inch bolts and a length that was the same as the 289 rod. To make up for the longer rod the compression height of the pistons was less and the top of the piston was bank specific due to the canted valves. (there was right and left pistons) The Boss mustangs continued through the 1971 model year and almost into the 1972 year but were dropped because of legislative action on the smog front. In 1971 there were three engines available in the Boss Mustangs - the smog 302 (not a Boss motor), the 351 Cleveland, and the Boss 429 (which was introduced in the previous year). In 1972 the Bosses were completely gone. You can get a 302 out of a Boss mustang that is NOT a Boss 302. PaulS
No, there weren't 'bank specific' pistons. When you rotate a head to the other side of the block, the pistons rotate right along with them as long as you follow the alignment marks on the top of the piston. You need to put that book away if that is what they said. I see they also claim the Boss block is the same as a 302 block. Wrong. Yes they did. The 351c was almost ready for market and Ford's TP302 was sucking really bad in the racing circuit, so it was a natural combo. Ford was really on the ball when it attempted to incorporate identical bore centers and bolt patterns to their different engine familys. Came in handy. No. In 71 there was only ONE Boss. Boss 351. The B351 was not available concurrently with either the Boss 302 or Boss 429. Some left over B351 engines were installed in 72s, but not labeled as "Boss". The B302 and B429 engines were FAR more valuable at the time for racing efforts and NEVER would have been put into cars as 'leftovers'. The Boss 351 was not built for racing homoligation, nor was it really anything special, frankly. It was a hopped up 351c, rather than completely unique parts on a low production engine. I don't even know where to start with this one! How can you have a Boss 302 in 71, but it is a 'smog 302'? Didn't happen. The Boss 429 was introduced in 69. Dave
So the boss 302 head isn't a 4V quench chambered cleveland head with modified water passages? Can you bolt a boss 302 head onto a cleveland motor by simply blocking the intake water passage and drilling a hole on the deck face or vice a versa for the cleveland head on a 302. Sounds pretty much like a cleveland head if you ask me! Or, were there actually combustion chamber and intake and exhaust runner differences? Or other differences? For the boss purist it may be important to have numbers matching boss heads but a good set of 4v cleveland heads will do the same thing for a lot less.
there are some cool things going on right now with cleveland heads. I have a set of aussie 2v heads because I want to build a bogus boss for one of my mavs. But I'm going to seel them in favor of aluminum heads. There is an Aussie company that is making a, what they are calling a 3v head. Looks to be a great head, BUT, now Edelbrock is offering a cleveland head that has all the mods made to it already to run on a windsor block (302 or 351). Still have to deal with the intake thing though. I have the price motorsport adapter plates so that I can run any 302 intake offered, there is also a co. that makes 2 intakes just for this ap, one dual plane and one single plane. Thack is already miles ahead of most of us going in this direction. I like the cool factor of the boss looking motor also, granted you can build a more powerful motor easier and cheaper with all the 302 parts out there now there is just something about opening the hood and seeing the boss type motor. As far as space because of the angle(pointed down instead of out) of the exhaust ports 1 7/8" headers fit. I don't know about room for plug changing. I remember reading about true Boss 302 heads that were tested, and they said that they didn't really come proper operation until 8000 rpm and went up past what they could turn the motor. They were definately not street heads. As for what is a Boss I think it has been covered well but we could try and get G. Johnson back on here.
Ward F this is Ward J! what are you running for pistons with the aussie heads?Also, the intakes you referred to were made by BA ??? They were called the street boss and track boss. I beleive they were/are based out of Arkansas. I understand that they may be back in business under a new name. Here is the thread http://mmb.maverick.to/showthread.php?t=889&highlight=bogus+boss You have several posts in these old threads as well so forgive me if I'm being to repetitive. I'm getting older so a few reminders are not a bad thing! I talked to bossmav about his 302 boss powered maverick. He was very helpful!! I forgot about trying 69-70 351C 2V headers in the maverick. Maybe it would work!
Ward, the Aussie company that is making the 3v head is CHI (Cylinder Head Innovations) http://www.chiheads.com/main.html PaulS, you need to throw that reference book away it is full of incorrect dates and data.
Holy cow Paul, there are so many factual errors in your posts I don't know where to start. Probably the most farfetched is the "1 in 3 302 engines in 71 was a Boss" LOL, that is so far from true I don't even know what to say.
Those CHI heads really out flow any aftermarket head that i've seen, but I have not seen that many. Man, they cost too but really might be worth it for the horsepower they make. I't maight be too much for a street car.
If you want a canted valve 302 engine the I highly suggest the new Edelbrock cleveland heads. With a simple modification to the water outlets you can bolt them onto a Windsor block (302 or 351), use a flat top piston and you've got a very nice street/strip engine that will make more power than most of you will need. There really isn't much price difference between the Australian and the Edelbrock once you get to modifiying the iron heads.