The Comet will be getting a 302 from a 1988 Merc. The heads are cast E6SE. Are these the 1986 heads that have small ports and are best avoided? Having no other heads handy to compare them with, what size are the small ports and what size are the larger ports? What "cc" are these heads? OR, where can I find this info myself? Since this is an intermediate engine I'm planning on just buying a "kit" with bearings, pistons, rings, etc, etc. But I can't order a kit until I decide on what heads to use. Thanks for any and all info. Sopp
Those heads are ok for lower end torque, but I wouldn't use em unless they didn't need a rebuild. I think they have 69cc combustion chambers and egr crap. For the cost of a rebuild you can get some better heads off of ebay. If you do use them, make sure you use flat top pistons to help compression. Best heads to get for the money GT40s or late 60's heads for 351w.
Ok, had to get my book 351W heads 69-77 are the ones to get... C9OE, D0OE, D0OZ, D5TE 60cc combustion chamber 1.84/1.54 valves (bigger than what you have) Or the late model GT40s I would also tear the engine down before you order a kit. It may not need bored at all. You never know. That would save some $$
The E6SE heads make excellant bottom end torque, but yeild 25 hp less on top than the E7TE heads. You're better off buying aftermarket heads than using the E6's.
MadMan21, thank you for the list of 351W heads to look for. Machine shop I'm dealing with has piles of Ford heads that are suitable for rebuilding. baddad457, thanks for explaining the difference. My Grandson is paying for the rebuild and is on a tight budget. Not sure he can spring for new aftermarket heads. I'm not comfortable buying heads on ebay without first hand inspection. Hopefully my machinist will have something that will work. As I said before, this is an intermediate engine. Something to run in the car while we build a real kicka$$ stroker------over the next couple years.
madman21 has the exact head numbers that are in my ford high performance interchange parts manual.they are 60.4cc. in 1978 they went to a 69cc head and 1.78/1.45 valves. good luck in finding them. if you have to have a lot of machine work done on them. like bigger valves, new springs, etc. you might just want to compare them with an aftermarket set in the summit catalog, or jegs. you'll pay more but the newer technology is worth it, if it's only a few hundred more.
The 351 heads will have bigger bolt holes than 302 heads, so you will probably need to get some stepped bolts off of Summit. If you go with 302 heads, 68-76 are pretty decent. C8, C9, D0, D1, D2, D5. Should have 58.2 - 63cc chamber and 1.78/1.45 valves.
I have a 302 ( with a bad knock ) from an early Mav. All the part numbers that I can find start with D3OE. Assuming the heads are also D3OE, are these worth rebuilding? Can I use flat tops rather than the dished pistons that are in the 1988 motor. I would like a CR around 9.5. I'm looking for a cam with a bit longer duration but not much more than stock lift since I have a set of 1.7 roller rockers. It's been so long since I worked on a small block Ford, I can't remember what works together and what doesn't. Advanced CRS.
The best heads you can get are 69-73 351w. 73-mid76 heads are almost the same, but have some emissions plumbing that can get in the way. Disclaimer: GT40p heads have a big following and are likely as good, but they have header fitment issues, so I ruled them out. The 73 302 heads are not what I would consider performance oriented. If you put some sweat equity into a really good port and polish, then they will be much better, HOWEVER, the same effort put into early 351w heads will pay off with much better results. Those heads flow as well as or better than many aftermarket heads when they have been worked properly. Make sure you go for screw in studs if your gross lift is going to be over .480"ish. That includes your 1.7 rockers. Press in studs are notorious for pulling out. The larger bolt holes in the heads can be dealt with 3 ways: Aftermarket shoulder bolts as mentioned. Aftermarket hardened shoulder washers. Or just ignoring them. I have washers for mine. I asked my uncle what he uses on his, and he said he didn't worry about it. He has run them on his 289 since the mid-70s! He says the dowels in the block keep the head in position and the bolt heads don't go into the holes, so why worry.
Pull the head off and find the number on it. It is probably a D2, which is ok. I'm not sure how much a flat top piston would improve your compression. There is a calculation for that.
The 88 pistons aren't really what you'd call dished, the dish portion is barely .040 or so deep. Plus it has no valve reliefs, and that's going to get you into valve clearance issues when swapping to other than E6SE heads. (the valves are sunk deeper in these heads than all other 302 heads, deeper by 1/8". this is the reason the pistons have no reliefs)The 88 Vic piston's pin height is also taller slightly. Replacing these pistons with flat tops with reliefs may or may not net you higher compression, that's gonna depend on the pin height of the piston you choose. Not all flat topped 302 pistons are the same height. They vary from 1.585 to 1.619.
