I have been digging around looking for a good aftermaket head. I was looking for a cast iron set. On Jeg's they have a set a World cast iron 200 Rousch heads for a 302. I have a 68 F100 with a '78 302. The local performane parts guy said these are good heads but they flow almost to well. Not sure what he means exactely. Question is are the heads from a 78 good as is or should I change them? Also does anybody know where the casting numbers are, so I can give you guys a llittle more info on the heads I got.

One more thing, if I install a cam with the following specs, do I have to change out the pistons for a set that have valve reliefs?

Advertised Duration: 272º
Duration @ .050: 216°
Lobe Separation: 110°
Gross Lift: .484''
RPM Range: 1800-5400

Thanks

Sanders

 

I believe the parts clerk. The Roush 200 heads are for all out race engines. They are designed to operate from 3500 rpm to 8000 rpm range. I would go with the Roush 180 heads, as they are designed to operate from 1500 rpm to 6500 rpm range. The Roush 180 head has a 58cc chamber, which is the same as a stock head. Thus giving you the same compression ratio as the factory unit would have. When you drive, what rpm range do you drive in? I think you will be happier with the Roush 180 heads.

 

With that cam you shouldn't have problems, seems an engine builder mentioned or I read somewhere, that a cam is usually okay if it has under .550" lift and under 220 duration, but you should check, its a simple process to check piston to valve clearance.


If your current motor is stock you probably have 69cc heads and somewhere around 8.2:1 +/- compression. You throw on a set of aftermarket heads with 58-60cc you can expect your compression ratio to go up.

You might also consider a dual pattern camshaft from comp cams, I believe your looking at a crane, look at the extreme energy camshafts, they provide more of engine vacuum than anything else, and more hp and tq. I have talked with people with mild 351w buildups and they seem to like the XE262 or XE268, comp claims equal operation ranges in the 302 for the same cam specs with a different firing order so it should perform fairly well in your 302 as well.


Just a thought but the ford gt-40p's 1.84/1.54 flow very close to the roush or windsor sr heads with 2.02/1.60 valves, as you can imagine the throttle response of the gt-40p heads should be a lot better. There is a company that can still get you a set of these with new larger 1.94/1.60 valves, 5 angle valve job stanless valves, springs good to .550" lift for $520 I believe, if interested I can get you the number. There is the issue of header fitment, but many people seem to find something that works. There are also a couple of people who port the e7 heads and have a following or good feedback, a set of these heads on a mild 302 should work out well, as it wouldn't be overkill for $500-600 completely rebuilt heads with springs, I have checked locally and that isn't a bad price. If you would like their numbers then lemme know and I will give them to you.

The casting number is on the bottom of the head, you can take the intake off, and put a mirror under the intake port and you will see a 4 character casting number, if original it should start with a "D", it will probably be D8OE.


Whatever you decide good luck with your engine build