I have an 88 F150 4x4 with a 351W jasper motor. Towing cam, headers, Edelbrock manifold and carb.
On the the question. Would I gain anything by using 1969 302 heads? LOL after a transmission (4K to replace) on my 6.2 GM 400hp went out, this poor antique feels under power. Yes I know that is takes a lot more to get a 351 up to that level. Just occasionally tow 6000# ( skid steer or 1950s tractors)

 

Using 50 year old heads would be a mis-step. By the time you pay for them, then pay a shop to machine them flat and get springs, valves and all the hardware... you could have bought a new set of aftermath heads.

 

'69 302 almost certainly have smaller valves.

There are better heads for the 351W but '69 302 heads are not on the list.

"In the day" people would put 351W heads on 289/302s for the larger valves, even though you took a hit on compression.

 

^Agreed.

And given what you're towing, I think a set of taller gears would be more of a benefit: 3.73, 4.10 or 4.56, depending on your tire size.

 

It is underpowered, depending on the cam you might have a 260hp motor there now but a decent set of heads could add 100hp. Decent heads for a motor this size would be something like AFR185's with a 60cc chamber to bump compression a little.

 

*supercharger*

 

They are certainly more digital than the beforemath heads...

​​​​​​​sorry... had to.
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the 302s would be free$ and usable condition, but if there a negative then I'll do something else.
3L55 gears are no help either, But I'm already 10 mpg. Then there is the cost of having to do two sets for 4.10
Never changed them myself so add labor to a 20 times a year truck.

 

Well, that’s not right. The ‘87 Bronco (302/C6) and ‘89 F-150 (302/M5OD/4wd) both consistently got 14-15 in combined city/hwy driving with 3.55 gears. I see you downgraded to a carb but your mileage shouldn’t be that bad. I’d say you have some tuning to do.

 

..... damn autocorrect

 

you could do a 5 speed swap. Have a better gear spread and an overdrive. That would help getup and go...AND give you less rpmat speed to help mpg.

 

Remember also that stock 302 heads will have smaller 7/16" head bolt holes. You'd be better off finding a set of Fox-Mustang racer cast-offs. Those guys get rid of all sorts of stuff cheap. I had gotten the heads for my 393W build - World Windsor Senior iron heads that had been professionally ported - for just $400/pr. Same price for a set of TFS iron high-ports.

 

Normal production heads for small Fords have always been poor. Even cheap aftermarkets are better, like bottom end Edel Performers, old FMS GT40X, etc.

Funny, been a while since I had seen anyone mention TFS irons. Yep, Stang guys dump good stuff cheap always.

Agreed that an OD trans would help. A mildly built AOD would my my choice if you want to stay automatic. It will easily hold the power with basic mods.

 

Funny you should say that... When I loaned my car to a buddy I had made the recommendation that it ran the quickest by shifting at 5300rpm. I had run a best of 13.06 @ 106.55 in a 4100-pound car/driver.

So what did he do? took it to 6500!!! That resulted in dropping an intake valve seat, and blowing up the motor - four pistons damaged from shrapnel flying around in the intake manifold, etc... Soooo rebuild time. Since the car was now age-exempt from emissions testing, the 22cc dish hyper pistons that gave the emissions-testing-friendly 9.4:1 were swapped for forged flat-tops, raising the CR to ~11.1:1. Since my iron World heads were damaged, I initially bought a set of as-cast RHS/Roush 200 aluminum heads. Dyno time: Now 506hp and still climbing at 6000rpm, and 430-480lb/ft for the entire pull from 3000-6000! AND all that with ill-port-matching 1-5/8 BBK shorty headers! Feeling there was more to be had, I bought a set of Fox Lake CNC-ported Edelbrocks (flow 308/238 @ 600!) and a proper set of 1-7/8 longtubes and picked up another 115hp! (Sadly, Ron Robart at Fox Lake has since retired and closed up shop...)

BTW, this engine is backed with a custom wide-ratio AOD (2.84 First compared to the stock 2.40) and 3L55s. Trans has the best of everything possible - bigger clutch packs, wider OD band, better one-way clutch, hardened inner input shaft, rear lube mod, and a Silverfox SPT-R valvebody that eliminates the '2-D-2 shuffle'... I also upgraded the converter from 2500 to a 3200 that still retains lockup in D and OD...

 

Yes, but I'm always afraid that the stuff they are getting rid of cheap has been used and abused.
My fear is is that I'd get a set of heads for $400, but then have to spend $1,000 at the machine shop to make them useable.