308 head questions, and porting templates

[greasydonkey]

I know mopar performance HAD them, but i cant seem to find anyone selling them anymore. Am i not looking hard enough, or did they quit making them? Anyone have any templates for the 308s for sale?

secondly, these are going on a 408 stroker with a supercharger. Would there be any real benefit to adding 2.02 intakes to these? The consensus I hear most is 'no', but those people arent running them on supercharged engines either.

thanks!

[Jacksdad]

Just finished reading a book on turbocharging (Street Turbocharging by Mark Warner) where the author talks about the misconception that porting isn't worth the effort in a forced induction engine. He says "The fault with this logic, however, is that any restriction in a flow path results in a pressure loss, which robs boost that you've worked so hard to create...". I'd read that to mean bigger valves would be of benefit in a blown engine too.
Wish I could help on the templates - I mistakenly bought a set for the 308s years ago and never got to use them (the counter guy insisted they'd work with my non swirl port heads). They got packed away during the last move and I wouldn't have a clue which box they're in. Good luck finding some. I can't believe they don't still sell them.

[dwc43]

The 2.02 vales would be a must for those heads, problem is those heads are not that good for a blower motor. I'd look for Edelborkcs or W2's.

[DartGT66]

Why aren't they good for blower engines? Propably the W2's ro RPM's would be better, but why wouldn't the 308's be at least as good as any other factory heads? I used them in the early 90's replacing bowl blended and port matched 2.02/1.60 J-heads with out of the box 1.88/1.60 308's. I did that for the unleaded seats they had, and wasn't expecting much performane wise. To my surprise, they really made a difference in my 360 despite of the small ports they have, and performed way better than the J's they replaced.

[greasydonkey]

some of the guys on here keep insisting on w2s or edelbrocks. i really personally prefer to use factory parts like factory heads as i like the factory look, and i dont want aluminum heads. w2s, at least the econos that i WOULD use, are hard to find and usually heavily ported when you do find them, so they are out too.

i specifically wanted 308s and have been looking for the whole 89-91 360 to get them and the rooler block at once. i got the whole motor and the 518 out of a 350 ram van for $217 at the pull a part. you cant beat that. again, these are the parts i wanted.

so to get back to it, anyone know where i can get the 308 templates?

and dartgt66, thanks for always being the 308 advocate and having the personal experience to back it up.

[Dart]

Just my .02...

I know you may not want the Edelbrock heads, but something to consider is the heat dissapation characteristices of aluminum vs. cast iron...the supercharger will generate a ton of heat and the eddy heads will help any potential cooling issue with heat dissapation. Thesse heads will also allow you to run more boost.

I love the 308 heads and think they will be fine. If I remember correctly I think the 308's are closed chamber? Obviously this will make a difference on your base compression ratio. If you are already set on the CR then the only other thing to consider would be the amount of time/money you would have in the 308's vs. a stock eddy head. You will have a lot of time/money into the 308's to get them to flow like a stock eddy. Putting the 2.02's in the 308 is a must for that application especially if you are going to port the 308's - make sure to have the heads "back cut" when you install the 2.02's.

[DartGT66]

308's are open chamber, teh major difference to the earlier heads is the exhaust port, which actually does have a short side and is smaller elsewhere, nice contour, and the pushrod pinch is way bigger, narrowing the port a lot. This is because of the lifter angles, and the hydraulic rollers used stock in engines equipped with 308 heads. You can open teh pushrod are to the same width as in the older heads stock, but not quite to the same width as in the older ehads, unelss you "sleeve" the pushrodholes.

[rumblefish360]

NOTE!

The porting templates are for a 1.88 intake valve.

The heads are fine for blown engines. Better when ported. The w-2 styled exhaust port is the biggie here.

[waynebo]

actually the 308's and the 576's that replaced them,,mopar parts only" are better than any other factory LA head because of the exhaust port..in blown motors getting out all thats been crammed in their is a big problem and the superior exhaust port on the 308 is what you need,,waynebo