If I could get paid for the time and energy I've devoted into figuring out a new solution for my rebuild SNAFU I would be able to pay to have an engine custom built!

But, no checks have shown up in the mail. So here I am with more questions for the collective. I don't know where Bill is, he can probably answer this question rolling over in his sleep, but maybe somebody else can chime in with the specs...

I've got a lead on a pair of rebuilt 78 351w heads for $200. Milled, new valves, springs, etc. According to the shop that has them, they're D8OE heads. Now, everything I've read says that these are just about the worst heads ever made b/c they have a 69cc chamber (vs. the 58.2cc my previous 302 heads had) and 302 size valves. However, all those sources also state that 78 and later heads have bolt on rockers. The shop says these heads (I haven't seen them myself) have rocker studs, and a quick cruise of parts suppliers show both pedestal/bolt-on rockers, and stud mount rockers available for the 78 351w. SO....

My question is: Is there an early 78 head and a late 78 head? If so the early would logically have the studs like the 77 and earlier models. Would it match the 77 specs in other respects?

77 351w Head specs: 1.84/1.54 60.4cc - used rocker studs
78 351w Head specs: 1.78/1.45 69cc - "supposedly" used bolt on rockers

Anybody have any insight?

Thanks,
Jim

P.S.>>>Anybody know if rockers from a 302 will work on a 351 head? Otherwise I'd have to drop $150 just in rockers, putting the heads up close to what it would cost to have my 69 D0OE heads re-done. (If I had the money to do that I would btw, rather than picking up 11cc's of combustion chamber)

 

what base block are you using?
The most important question is "What do you want your engine to do?"
Second is " How much do you want to spend?"
You have 3 choices for heads 302,351w,351c.

 

Now for what you specifically asked...
Here is what the Summit applications splits out for a set of 302 roller rockers.:

Rocker Arms, Stud Mount, Full Roller, Aluminum, 1.6 Ratio, Fits 3/8 in. Stud, Ford, Small Block, Set of 16

Make: FORD
Beginning Year: 1968
Ending Year: 2001
Engine Type: V8
Liter: 5.0
CID: 302
Engine Size: 5.0L/302
Engine Family: Ford small block Windsor

Make: FORD
Beginning Year: 1969
Ending Year: 1997
Engine Type: V8
Liter: 5.8
CID: 351
Engine Size: 5.8L/351
Engine Family: Ford small block Windsor

 

If your pistons are set up for the 58cc chamber heads, you don't want to run the big chamber heads. You'll lose too much compression and have a horrible running engine. Sometimes the "good deal" isn't so good after all.


Can't say for sure on the chamber size vs. rocker mount style question, but the pedistal mounts were a running change so there could be versions of both of everything running around. If you have a set of early 351w heads, they're worth putting the money into to make them work. Intake valves and ports are much bigger and will make a big difference in your driveability. You won't be sorry. AFAIK, rail rockers will interchange on all of the heads that use that design.

 

Thanks for your responses guys.

I've got a stock 69 302 in my truck that I've torn down. The machine shop came back with a very tall order for head work, plus some other work, sending me searching for options. This was one lead I found that started out sounding pretty good. They were initially offered with a short block 351w. Together they'd probably work fine, but the parts I'd need to fill out the 351 make it almost as expensive as the laundry list from the machine shop. Then I found out about the 11cc boost in chamber and since the stock compression ratio was rated at 9.5. I don't know the proper math, but if an 18% increase in size yields an 18% drop in compression would drop it down to 6.7.

My truck is my daily driver (save for a winter beater that guzzles gas) and not a hot rod. Someday I'll build the tricked out hot rod of my dreams, but this is the truck of my dreams; a reliable, economical, faithful ride. Something I can afford to drive, with just enough power to be fun. I've had that in this truck with the stock 69 302, but over the years compression went down. Now that it's apart it's apparent it was the unleaded gas destroying the exhaust seats. 40 years of wear is not cheap to fix.

I've got a C9OE-C block, and D0OE-B heads. Despite the D0 indicating 70, the heads are stamped 69 302. The date code on the block is 12/8/69, so this was obviously a late 69 engine. Good heads. Good block. But a lot of money to get them back in shape after 40 yrs of service. (Everything internal shows to be original; bearings, connecting rods, pistons, etc.)

Thanks for the input guys. We always start out expecting one thing, and then end up with something totally different. Shoulda known!

Jim

 

You can't go off the summit info to determine what you have or need. Rocker studs are an easy and cheap fix to convert, so maybe the shop converted them to studs. The shop should be able to tell you what the cc of the heads are, just ask them. Rockers (stud mounted) are interchangeable between all the small block windsor fords. You can not use 351C heads on your 302 because it requires the one thing you don't have, open ended funds. This is a very expensive ordeal and they would have to be 2V heads to even work worth a crap on the street.

As far as the cc's of the head that is not a big deal because I read another post that you need to bore the block and get pistons so you can get a piston to bring your c/r back to a good streetable number.

 

To answer the question, no, 18% increase in volume doesn't equal an 18% drop in c/r.

 

If you didn't change anything else, the 69cc heads would yield a compression ratio of 7.8:1 The 58.2cc heads would give you 9.28:1 These numbers are all for a 351w with a 3.5 inch stroke. I'm assuming that if you get the 351 heads you're also thinking of getting the 351 short block.

As Dave points out, you could use different pistons to up the compression ratio, but another thing comes into play....the cam. The intake valve doesn't close at BDC at the end of the intake stroke....it closes after the piston starts coming up on the compression stroke. The practical compression ratio starts at whatever the piston position is when the intake valve finally closes. Different cams will have different lift and duration, so you need to look at that point to determine if you're overdoing it, or building something that will run on pump gas.

It is rewarding to build a fresh engine, but 302's were used in a lot of cars and trucks. You could consider a low miles wrecking yard 302 as a bolt in replacement for yours. I have done a few over the years....when I ask the answer is always the same....this one has about 75k miles on it!!

Dan

 

Well a 302 punched out 30 over would need flat top pistons and zero deck to achieve 9.11:1 with 69 cc heads.

The junk yard option would be a cheap option. Even if the engine isnt good, heads could be taken. If your goal is fuel economy and daily driving, the efi could even be swapped.

You have options, sometimes the choice is the hardest part.

 

I admit I've got several threads running as I try to figure out what direction I'm going to go. It's hard in that case to remember what's been posted where.

Within about $400 of each other I had/have four options.
By order of price:

1. Buy a reman 302 long block. 3yr warranty from a widespread chain.
2. Rebuild my 69 302 and D0OE Heads
3. Get a 351w block with rebuilt bottom end and D8OE heads
4. Rebuild my 69 302 block (bored 20 or 30 over) and put the D8OE heads on it.

Option 4 was about $400 cheaper than option 1, but only about $200 cheaper than option 2. By the time I scrounge the 351w parts that I'd need to make that work, options 2 and 3 are only about $75 bucks apart.

The good news is, last night I lined up some side work that can help fund this project. It's the amount of work (and subsequent price) that sent me reeling. Praying that this work pays out what it promises, I think I'm ahead to rebuild the 69 I've already got. Then I don't need to worry about unknown parts, build quality, or conversion/compatibility issues.

The goal is to have a healthy, economical daily driver that my wife and I can take on an anniversary trip this summer. We took the truck on our honeymoon 10yrs ago and I just wanted to make sure the engine was squared away before we took it on a long cruise.

Thanks again for your help and input. I was really leaning toward putting those 351w heads to save myself $200. Sounds like I would have ended up regretting that idea.

Peace,
Jim

 

FWIW, I think you're on the right track. Rebuild what you have and know. Changes usually end up costing more chasing the unknown issues that always seem to arise. Remember, time and frustration levels are worth something, too. Best wishes on your project.

 

If economy is more important that total power, you should check your local craigslist for a good running 289. It may be a long shot, but worth checking into.

The only concern between 289 and 302 that I am aware of is the very early 289s had a different bell housing bolt pattern.

 

Looking around the craigslists in your area found some interesting things, maybe helpful, maybe not:
SBF Ford Heads for 302, 289, 351w
FORD 289 CRANK
Ford 289 Pistons
1967 ford 289
Ford 302 motor (D8VE)

 

I have mixed feelings about the chain store version. I have a 95 Off Topic 3/4 pickup that I use as my utility vehicle....around the house, camping trips, towing etc. When it needed an overhaul I bought a store brand overhauled 5.7 liter 4 bolt engine for $1400. It runs OK...after I re-adjusted the valves which were way too tight. It does make a funny sound that is probably the metal timing chain on the metal gears....the factory used nylon coated gears, so I'm OK with the metal. Between the funny noises, and the fact that I can't do a complete overhaul for $1400 makes me a little concerned (how long will this one last???). At the time, I didn't have a lot of spare time, so the engine change with the store engine was a weekend job...that was a real plus. The thing that sold me is that it has a warranty.

For my 52, I went with a 351w. It came from an 89 F150 donor truck. I got an exceptional deal from a guy who had all of the machine work done, but lost interest in the project before he assembled it. I did set it up as a carbureted engine and used a cam and timing gears that are essentially stock equipment for a 1969 engine. With the compression ratio of 8.5:1 it has a lot more torque than other small blocks that I have had in the past, but it is really pretty close to stock.

Dan