318 head swap......how to?

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17dartandbroke

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I just got a performer intake from member jason69r. and my valve seals have just started to go out. the car smokes only on startup, so that is what i am guessing that it is. i am thinking about finding some 302 casting heads and putting them on my dart. i was just wondering what thickness head gasket and what brand will i need. also, what work should i get done to the heads? i am doing all of this because i am planning on installing nitrous on the dart and want everything to be right before i do so. do i need any special new bolts or anything like that? just what should i get before hand so that the job can be done in a weekend because i have to drive the car to work during the week.

thanks for the advice,
daryl
 
The 302 heads will raise your compression ratio quite a bit if you're not changing anything else. Not necessarily a bad thing, unless you can't afford to buy 93 octane gas all the time.

Here is a great artcle to read.

http://www.geocities.com/MotorCity/2398/engine/Pitcher.html

Some basic porting and larger valves can make these heads work very well.

I was thinking about using 302 heads on my 318 Dart, but decided to build up a 360 instead. I had already bought a set of used 1.88/1.60 valves to use, but obviously I don't need them now. If you decide to go this route and want the larger valves, I'll sell these to you real cheap.
 
The 302 heads are pretty good. they ave smaller closed chambers for more compression and are heart shaped for better flow. But they are also 20 years old now so make sure you look them over before bolting them on.

New head bolts would be a good idea. Mopar Perf. sells a thin gasket thats about .026" thick for alittle more compression aslo.
 
one other thing

can my valve seals be changed without removing my heads? and would you reccomend me doing this instead prior to installing nitrous?
 
yes you can change the seals with the heads on the car. YOu'll need to make a fiting for an air hose that will screw in the spark plug hole to keep the valves from dropping, then remoce the springs. May aswell put some springs on it too.
 
that is what i am going to do then when i change the intake. we already have the fitting set up for the air compressor from when we changed the springs on my dad's cutlass. would that be sufficient for nitrous?

thanks,
daryl
 
aslong as he short block is in good shape and your staying around 100 horse worth of nitrous you should be fine. Just back the timing off a few degrees and run some good gas.
 
thanks for the advice. im going to see if i can find a set of heads anytime soon, and if not i think that the motor will benefit greately from just the seals and springs being changed..........being that the ones on there are the stock ones.
 
Also just a not when going to 302 heads on a stock engine you will NOT need to run 93 octane! On my 302 headed mill it would run great on 87 oct. with no pinging!
 
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