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Discussion Starter · #1 · (Edited)
I took 2 sets of Magnum heads that I have had sitting here collecting dust for mag testing and (hopefully) drilled to accept LA intakes; ALL 4 HEADS CRACKED! $96 down the tubes for testing;+ the $225 I paid for the 1 set that was supposed to have come off of a 380HP Mopar Perf crate 360. Damn!

That's AFTER I took a set (that makes 3 now) to a local machine shop for that mod, a set that I know to be crack free; but I "assumed" I knew the angle of the intake bolts; the shop did exactly as I asked (my bad) at least that set is still perfectly useable as Magnum heads WITH a Mag intake; $50 wasted there (I guess the heads are lighter now anyways)

so I found a deal on the Engine Quest heads for $245 each; bare but all machined, ready for my valves and springs; had I done that in the 1st place I'd be way ahead. these are the heads they used on the "400HP 318" in Popular Hot Rodding magazine. My wife's gonna KILL me when the CC bill comes.

I started out as having 3 good sets of magnum heads (I thought) and my truck with guide trouble; so I figured WTF why not put the Mag heads with the fresh valve job and ported on instead of having my original '83 ones redone? so, I got all the conversion parts that I did not already have.
So once I had all that, and then found that my heads were junk (and I messed up the only good set, typically my luck))
I am in "too-deep", in parts acquisitions, to stop now. so I took the plunge. so hopefully not this weekend but NEXT weekend I should be able to swap out the top end on my truck. about a point increase in compression, 1.6 instead of 1.5 rocker ratio, will be like putting in a "RV" cam, and adding a Performer and AFB should hopefully wake that thing up a bit. Now to dump the single exhaust for true duals (catless at that) and that 318 oughtta RUN!

I stopped at a local exh shop for a piece of 2-1/2" "scrap"; the cat comes out tonite! (I want duals but can't yet now; c'mon tax refund!) and I also have a couple Carter AFBs (4, actually) incl (1) Eddy version with manual choke (not likely I'll use that one) a 500 CFM version ("9511") and 2 625s (9635 and 9636) all elec chokes.
 

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Discussion Starter · #2 ·
I'd like to see what you guys think; how will this thing run? HP, TQ, MPG (driven "decently") estimates; I was at 13 before the cold snap hit, towing my Cherokee home from WI on the truck's maiden voyage (I bought the truck via Ebay 335 miles away from here) I got 10 and it was hilly up there, and I had not had a time to drill out the seal plugs and correctly adjust the carb; 10-11 lately, no matter how I drive it, with LOTS of "choke-on" time.
MPG wise if I was REAL worried about it I would not be driving a 3/4 ton truck! But I want it to be (stealing an old Army slogan) "the best it can be", for what it is.
I got 22 on the hwy with my TQ equipped '81 W 150 and mt '79 D 100 with the '69 318 in it, so thats what I'm shooting for! but more importantly "more power" for the times I USE it, as a truck gets used!

Power-wise, with the EQ heads I should have the same CR as the late 60's-1970 318s with the smaller combustion chambers which would be 9-9.25:1 and with the higher rocker ratio compared to LA stock rockers it would be like adding a mild RV cam, plus with much better flow from the new heads. Add the 4 barrel Performer intake and the AFB, and I'm hoping for maybe 250HP maybe a bit more; (though I know that up til '71 they were rated "gross" HP, instead of the later "NET" ratings (mostly "on paper" engineering guesses). that said, is the 150 HP rating of '72+ motors actually better than that? (some around '80 or so, in cars were NET rated at [gasp!] 120 in the Chilton and Mitchell books) but back to 150 (2bbl) and 170 (4 bbl) by the mid '80s when the '302 heads came out.
So cmon guys tell me what you think!
 

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Mopar Madness - Get it...
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My wife's gonna KILL me when the CC bill comes.

Join the club. ;)
(I've found it best that when the mail comes, to be in the shop/garage with the doors locked and a six-pac so you can hole up a while.. :D )
 

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Aka Force Fed Mopar
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I think you shoulda just done the seals :p But I would guess you'll have around 200-220hp. BTW, if those heads are just cracked between the valves, like small cracks, they are usually still usable. The 2.2/2.5 heads were like that (especially turbo cars), almost every set you see has cracks between the valves, never causes problems though.

And just FYI, my '87 Diplomat's 318 was rated at [email protected] (IIRC) w/ the 2bbl, 302 heads, factory roller cam and the Lean Burn system. I think the 4bbl cop cars had 170hp.
 
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