I have an early to mid 70s 302 from a ford truck, I know next to nothing about fords. I have been considering rebuilding it for my sons ranger. it has a 2bbl intake and I was told it has 2bbl heads. my question is what are the difference in 2bbl heads and others? I want this engine to be a mild performance street engine but dont know whether to toss the heads or keep them. I assume a 4bbl intake will bolt up fine but will the heads be an ok choice. thanks

The heads without knowing their casting numbers will most likely be an open chamber, low compression head. Things cam down pretty fast in the 1970 to 73 time period. Anything after that will all be low compression, after 75/76 will have hardended valve seats for no lead fuel.

The 4 bbl intake will bolt to your existing heads. Remember that any milling on the block head deck or on the heads, also needs to be compensated for on the bottom and sides of the intake.

Bogie

The heads you have are the worst for performance on a 302,check with some of your local machine shops you can probably use them for cores and have them set you up with the E7 heads, porting the exhaust and grinding down the Thermoacter bumps and going to a 1.60 exhaust valve would make these work for you.If its' in the budget take a look at the Windsor Jr. heads from World in the Summit catalog.Choosing a cam for the 302 is critical also due to the weak exhaust flow so always use a split duration that has more duration and lift on the exhaust.Ford had different length pushrods so be sure and get the ones that match the heads you end up with.

If you can find a low mileage pair of GT40P heads from an Explorer you will be time, money and effort ahead. If not, the price of after market heads is really cheaper then a quality rebuild. By the time you replace valves, springs, rockers, valve guides, plus throw in a seat or two and did a good valve job, you will have come close to equaling the cost of the new heads. Been there.......... but before there were so many great after market Ford parts. Any good 2 plane intake and a max 600 cfm carb and at least an Edelbrock Performer level camshaft plus a decent exhaust will wake up a 302/5.0L. Pick up a book from Borders - "Ford Windsor Small-Block Performance" by Martin. It's a little bit dated but still a pretty good background source.

Dave W

With the exception of the Boss heads there is little difference between the 4bbl and 2bbl heads. All 70s heads would be considered 2bbl since they didn't make a 4bbl engine. The only 4bbl 302( except the Boss) was the 1968 302. I disagree with some of the comments regarding early heads. Tests have proven that they work as well as later ones when treated right. The main drawback is the lack of hardened seats, but at that age they probably need a total rebuild anyway.

Depending on budget, I would go with a set of used GT40Ps, or if a few $ more is ok, aftermarket aluminum, the weight difference might be nice in the Ranger. Don't over-carb it, 302s suffer in the mid-range from too much carb, and in a Ranger you probably won't use the top end much anyway unless you are racing.

I agree with WOODZ428--Performance wise there isn't much difference in those heads and later model ones. The early heads lack hardened valve seats and the rocker studs are just driven into the heads, which arn't good if you plan to add any extra lift to the valves.

I recently finished a 74 F100 302 build. = Here's what I put into it:

E7 heads == Edelbrock Duel Plane Performer Intake == Edelbrock 600cfm Performer carb, (jetted for economy).==== Cam - 204 / 210 duration, 448 / 472 lift, 110 LSA, RPM range 1500 - 4000. ===Full headers== Tuned duel exhaust system with "H" pipe.

I was hoping for a good bit of additional hp. I then planned to go to a higher rear end gearing as a way of improving mpg figures.

The built engine performs just a small amount stronger than the original. Runs good, strong low end, but overall "up hill" pulling power increase is very small. MPG comes out to 16 mpg open highway driving like gramma and staying out of the secondaries all together.

Ford Heads are great for a stock rebuild. They have small valves and small runs as a way of maintaining a strong low rpm velocity to produce a strong low end torque. They do that well - the problem is when you try to get more to go through the heads. It just doesn't happen.

If I were to build another 302 and attempt to gain hp the first thing I would do is get a good set of aftermarket heads and start from there.

Many thanks to all of the great guys on this forum who fed me information on the engine build. (And most recommended different heads, though E7's were frequently recommended>) This is the best forum that I know of for high end knowledge and respectful answears to those asking questions.

With Ford small blocks, the only time you really need to be concerned with the difference between 4bbl and 2bbl heads is with Clevelands.

When I began hotrodding small block fords back in the '70s the the quickest and cheapest way to get bigger valves and better breathing on a 302 was with a set of 351W heads. You had to get very early heads, because at some point in the '70s (71 or 72 if memory serves, and unfortunately it does less and less) Windsors started getting the same open chamber small valve heads as the 302. Now you have better options. But if you can find a set of very early 351W heads they'll still work.

This is correct - and the 351W heads to look for are the D0OE-C or G or the C0OE-B or D. These had 1.84 intake and 1.54 exhaust valves with 60cc chambers. Most needed to have the hump ground out of the exhaust runner, but not a big job - you don't even have to plug the hole if there is one. Not sure when they went to the smaller valves, but do believe that it was in '75. The '76 for sure had the small valves( I had a sets of '72 and '74 D0OE but took the last ones to the dump).

This is all good info - but my last set that I ran cost over $1000 to be rebuilt correctly . GT40P or after market is really the best way. Oh yeah - you need either special bolts or bolt hole inserts to use 351W heads on a 302 (1/2 vs 7/16 bolts and thru water passages)

Dave W

Dave W

If you change heads you'll have to make sure that your compression will be where you want it. The small block Ford heads had a lot of different combustion chamber sizes and you'll need the correct pistons to get the desired compression.

Danny