C4OE Heads; Cobra ?

Hello to all,

The guy I purchased my car from (bout 8 yerars ago) said the car had original cobra heads.

I am having an engine tune up and my mechanic says I should upgrade my heads to some 5.0 (1990) heads he has laying around the shop.

I asked him why he beleives 5.0 are better then my Cobra's? He said my heads are 54.5 cc 1.67(I)/1.45(E) therefore thinks they are not HiPo with those specifications.

I did a search and found C4OE-B are HiPo's. My casting numbers do not have the letter "B". In fact I cannot find anything on just the C4OE casting numbers.

Should I switch heads? are 1990, 5.0 heads better then what I have now?



I have a cam with the following specs.

Duration @ .004"Lift: Intake 290˚ Exhaust 300˚
Duration @ .050"Lift: Intake 224˚ Exhaust 234˚

Lift @ Cam: Intake .310 Exhaust .325
Lift @ Valve: Intake .496 Exhaust .520

Timing @ .050 Lift:
Open Close
Intake 5˚ BTDC 39 ˚ ABDC
Exhaust 54˚ BBDC 0˚ ATDC

Centerlines: Lobe Seperation: 112˚
Intake Centerline: 107˚

Duration @ .004"Lift: Intake 290˚ Exhaust 300˚
Duration @ .050"Lift: Intake 224˚ Exhaust 234˚

Lift @ Cam: Intake .310 Exhaust .325
Lift @ Valve: Intake .496 Exhaust .520

Timing @ .050 Lift:
Open Close
Intake 5˚ BTDC 39 ˚ ABDC
Exhaust 54˚ BBDC 0˚ ATDC

Centerlines: Lobe Seperation: 112˚
Intake Centerline: 107˚


Any help would be great!!
 
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Look at the heads in the valve sides, if they're genuine Hi-po heads, there will be cast in spring pockets for the valve springs to sit in. The Hi-po heads were the only ones to have this feature. They will also have screw in studs with no guide plates. (but this could have been added after the fact by anyone) The "B" suffix will be on one of the other intake port undersides. And if they turn out to be genuine Hi-po's, you can easily sell them or trade for the aftermarket heads of your choice. These will be worth big bucks to a collector. The two features I listed are the only things special about these heads, otherwise the ports and valves are identical to the std 289 heads. So in effect your mechanic was partially right. If you're after more performance, sell em and get better heads
 
If you're putting them on a 289, then no, they're not the best thing. The 10 cc difference in the combustion chambers are gonna make your compression ratio take a dump. You'll loose at least 1 full point. And with the cam you have, that's the last thing you want to do. That cam needs at least a 9 or10 to 1 (or better )comp ratio. If you have a 302, then the E7's are fine. You can mill the E7's .040 and get em down to 58 ccs (they're 64 cc's stock) and then you'll only give up about a half point in the ratio. Mill em farther and then you may have to mill the intake, that aspect needs to be checked BEFORE milling though. At a minimum, the intake bolt holes will need to be enlarged to compensate they're movement toward the centerline of the engine (with a more than .040 mill)
 
The 1990 Mustang heads (E7TE casting number) really arent the greatest either, but probably an improvement over your original heads. Some clean-up porting on the intake and opening up the exhaust a bit will net you a world of difference. Or just get a set of gt40 cast iron heads. Approach gt40P heads with caution as they have a relocated spark plug angle that can interfere with headers. I believe the stock manifolds clear the gt40P spark plugs (somone correct me if Im wrong here), but the early gt40 (no P) have the old plug angle and flow much better than the E7s. A good set of used gt40s will set ya back less than $400, so in my book theyre the best option for a mild performance engine. If you decide to go this way, these pics should help you (or anyone else) identify the different heads.
gt40andPheadsplugs.jpg

gtp03.jpg

4 bars = GTP
3 bars = GT
 
i'd definitely look for a set of gt-40 heads if you're going to go with a late model head. i think D, 1 point compression loss with the E7 heads (or any 64cc head) is a little optimistic, i think you'll likely end up with more compression loss than that on a 289 and probably end up somewhere in the mid to high 7's compression wise, not a good thing. if you're running the stock exhaust manifolds or even better a set of hi-po manifolds you might want to consider the gt-40-p heads as they have pretty small 58cc chambers and won't result in near the compression losses as the e7 or gt-40 heads, if you're running headers or plan on running them the gt-40 heads would be the best stock choice in a late model head if you don't mind milling them a bunch. IMO, the best head would be a set of C90E or D0OE heads and grind out the thermactor bumps and do a little bit of milling on those, they have 60cc chambers so you'll need to do some milling on them to get the compression back where it needs to be too. of course the best option would be a set of aftermarket heads though.