D8OE-AB Heads in my MII Stock???

Discussion in '1974 - 1978 Mustang II Talk & Tech' started by Addicted_2_II, Dec 8, 2005.

  1. I just tore apart the old (Original) engine that came with my mustang and it has D8OE-AB Heads on it??? I looked those up and it says they only came on 351W?

    Anyone else have D8OE-AB Heads on their MII's? Mine is a 1978...

    What heads came on your V8 MII's Stock?

    Very Strange!

  2. If I remember right, the 302 and 351 started using the same heads somewhere around '77 or '78.
  3. Yep I think this is what it was...

    They have larger valves but also a larger bowl = Less compression ratio than the ones I have currently on my MII.

    I really can't decide if I want to put new heads on my MII or not. I really do not need them but it would be an "EASY" way to reach my goal of 13.xx seconds in the 1/4mile!

    Right now I have:
    - 66 289 Heads 54cc 1.67/1.45, Built in Guides
    - Heads (Stage 1 ported, polished HD Dbl springs, etc...)

  4. All 260, 289 and 302W(non BOSS) heads have the same size valves (1.78"I x 1.46"E) and ports, even the rare HIPO 289 heads have similar small valves. The only variation in the small block head was combustion chamber size and shape, and smog bumps in the exhaust side. The exception to the rule is the 1969-1974 351W heads, which have larger valves, (1.84"I x 1.54"E) slightly larger ports and much larger combustion chambers. The obvious disadvantage of the bigger combustion chambers is lower compression when used on a 302, but the benefit of those larger chambers is unshrouded valves, meaning better flow, especially if you increase the valve sizes. You can mill the '69-'74 351W heads to some degree, and also have the machinist install thicker valve seats, so that the closed valves protrude slightly into the chambers, both tactics will decrease the volume of the chambers for more compression. You can also use pop-up pistons to get the compression way up, but then you will impede the flame front travel across the piston, and will lose some efficiency compared to a similar-compression flat-top piston setup. Years ago, it was a good economical tactic to use the milled 351W heads on a 302 with just the bumps in the exhaust ports removed, but with the cheap availability of serious flowing aftermarket heads for the 302, the 351W route probably isnt the best choice in most cases. Especially since those old 351W heads arent all that common anymore.
  5. BT,
    My 1966 289 heads have 1.67/1.45 valves in them? But also have 54cc Chambers! I think I just need to get aftermarket Alum. heads!
  6. I've never heard of 1.67" intake valves in a Ford head. Was it possible that someone mis-measured them? The only 1.67" valve that comes to mind is the exhaust valve of a 2bbl cleveland head.
  7. [​IMG]
    Here's a useful table for the SBF.
  8. That's interesting, of the few old 289 heads I worked with, I recall them all having the same 1.78" valves as the 302 heads. Maybe after 20 years, someone had replaced the original smaller valves with the more readily available 302 valves during the head service. Either way, thanks for the links, I will store that info to memory. I had no idea what size valves the 221 heads had, as I've never touched a set of those, but all I have to say is, 45CC chambers would give some incredible compression bolted onto a 351W. Talk about low speed torque.
  9. Yea I am running 54cc heads, that is how I am able to get 10.6:1 with mysetup.

    Thanks for all of your great feedback Blue Thunder!