ok to get started i found out i could build a 302 boss out of a 302 windsor block stock motor with a few modifications first step was to build a stud girlde for the high rpms second was use heads from a 351 clevland had to drill a few auxiliary coolant holes but dont know much about motors so i need some advise on what kind of 4 barrel intake will fit this beast any help would be great so i can finish off the motor part of the 73 mav. im slowly restoring
You have to use an intake made for the Boss 302. Honestly, most sources I have seen agree that aftermarket Windsor-style 302 heads will make more power than 351C heads anyway. And your intake choices are limited.
There is a weight penility and you have to put in Boss type pistons because the valve configuration is canted. I believe the rod length is different. There needs to be a .800" hole in the intake faces. Plug two square holes in the head to block surface, use Cleveland head gaskets and the intake manifold is unique to the setup. The correct push rods and a decent cam needs consideration. It has been done often. Do you really want to do this? There will still be exhaust issues. The heads stick out wider and the ports are at a different angle. The info for this head conversion is in the Ford SVO catalog along with a lot of other info.
K Merring is right, the weight and port angels will kill you, if you want cleveland style heads then go with the whole engine, will windsor style heads out flow the cleveland, no way, you have to spend large sums of money to get them to flow as good as the cleveland even the best style alum heads. the boss 302 was a windsor block with a cleveland head right from ford. now when it comes to intake manifolds there are a few cleveland styles that are ok but a much better selection for the windsor which is why i run a windsor style intake. now if your heart is set on this, then try to find the aussie heads.
No, the windsor heads will not flow as well as the clevelands. But the 4V heads flow way too much for any street car anyway. The modern aftermarket windsor heads are smaller but usually make more power on a street car (from what I've read).
Really! If I'm not mistaken the fastest production street mustang untill the Mod motored R was the 71 Boss 351
You both are right. The difference is that the Cleveland heads flow a gang of air up at high RPM beyond normal street use,(drag race conditions) and are poor for street. The aftermarket Windsor heads will perform better at more practical street engine speeds. Like pulling soda through an 1/8" straw and trying to do it through a 1" straw. The 1/8 is more practical.
I'm sure that's wrong; the '71 429SCJ was faster than the Boss 351, and surely other big block Mustangs were faster, like the Boss 429 or the '68 428CJ. Of course magazine articles back then were pretty misleading, as were HP figures.
Ok if thats the case then why didn't the FI 351W R out perform the 71 boss it had all the modern parts, i agree the cleveland is a differant animal and that it needs revs to work, but in the case of the W you are talking a torque monster that wants to rip the tires right off the wheels so you have to work to get either to work. i run my car on the street, on pump gas, through SoCal rush hour traffic, the guy next to me with the windsor has nothing on me and i have a 3 inch straw. it just didn't sound to me like madmav wanted to be to practical if he does then by all means run a FI 302
jusy cuz wellin addition to my post the motor is almost complete i have about $1500 into it already building it up from the block its not very often you see a 302/351/or a429 boss any more so its more like a conversation peace for me and my gear head friends and need help finding an intake for it so far to my understanding i need a 302boss intake but every where ive looked i cant seem to find one any suggestions i live in fort worth texas if anyone knows a website that carrys them or a store in my area i would like to have the info please i dont know how much longer a can stare at the half build motor before i go nuts
The Cobra R 351W did NOT have aftermarket cylinder heads. Besides, IMO it did make more power. Is there a gross to net conversion out there? Because the 1995 Cobra R had 300@4800 365@3750 13.67@102.82mph 3501 lbs And the 1971 Boss 351 had 330@5400 370@4000 14.1@100.6mph 3452 lbs But those are not comparable numbers. The 1971 Maverick 302 had 210 HP (gross), the 1972 had 140(net). They were the same engine. So with the newer style HP ratings looks like the 351 W came up on top. It sure was a lot faster through the 1/4 mile (while being HEAVIER)
Get a set of Austrailian 302 heads... 351c 2v heads with closed combustion chambers. Then look for a B&A Street Boss intake. This will give you a Boss 302 that has plenty of punch for street driving. Go through Tubular Automotive for your headers. The angle of the exhaust port on a Cleveland head is better than that of a Windsor head when it comes to fitting in the car. The Clev. ports aim at the ground while Wind. ports aim at the shock towers and are actually tighter.
