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DART66GT

DART66GT

62 Lancer GT - B Body 8 3/4
FABO Gold Member
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I am planning to swap a 318 into my 66 dart /6. ( 4 spd. O/D with 3.55 SG 8 3/4) have gone thru a lot of old posts and am interested probably in an 87 Diplomat motor. What other years and cars had this same motor? And what else should I be looking for or avoiding in this type of 318?
 
any 318 newer than mid 70s is going to have low compression, pretty much involving an engine rebuild to get it up to performance standards, if that is your intention?
 
I am planning a mild rebuild. 2 plane intake, cam and 4 barrel. I was under the understanding that the 87 302 head motor had decent compression.
 
Maybe for it's time. Realisticly, you do not want to exceed 9.5-1 on a iron headed engine unless the cam is really on the big side. Decent power can be made with a 8 - 1 motor, but compresion is free HP and torque. If your cam is small, a 9-1 ratio will do well.

If your looking at newer engines, but still pre-magnum, the 318 also came as a roller motor. The 302 heads tend to crack inbetween the valves. A magnafluxing will let you know.
 
This is to be a fairly mild rebuild with small cam, dual plane and 4 barrel. 340 exhaust manifolds with dual exhaust.
 
I'd suggest looking at any 318 from around 85 to about 91 from a truck van or dippy, this should get you what you are after. Someone told me recently that the stock cr on these motors is in the high 8's. So theoretically if you shave the heads a little and use thin gaskets you can get a solid 9 to 1 motor out of using more or less stock parts. If you replace the pistons Ive heard that the 318 magnum pistons give a little more CR in the older motors, and are a direct replacement. If you intend to use the #302 closed chamber heads - plan on porting and increasing the valve size, for a mild 318 use the stock 340 cam. You could also use the magnum heads more or less as is and be good to go and save money and time over the #302 casting head. The magnum heads require a conversion that is all do-able using stock parts.
 
You know, I was thinking about mentioning that. About the Magnum heads. They do flow better and have a better balance between the ports flow numbers. It's actually a good idea.

I'm also thinking the late '80's 318 had a 8.5-1 ratio. Not bad at all. A trueing of the head , AKA light mill should be all thats needed. 8.5-1 isn't bad. If it were myself, I'd opt for a wider centerline cam with that ratio or lower to help the cylinder pressure stay high rather than bleed it off with a 110 or lower C-line.

Just thinking outloud kind off.
 
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