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Discussion Starter #1
hey i have a 1977 dodge stepside with a 318 it was stock with the 2bbl and know it has a Edelbrock performer intake with a edelbrock 600cfm carb. The intake and carb really woke it up, way more respronsive. i was wondering about what hp and torqe you guys think i would have? And what would be a better thing to do, headers and duel exhaust or a cam what would help more? i plan on doing both just dont have the money.
-jared
 

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Hi Jared, welcome to the forum. Both things work well with the 318, a good strong engine overall, neglected on its capability really. Being the intake valves are small in the 318, headers really don't show much improvement on a street engine with the small valves, but dual exhaust will help, add a cross pipe near the rear of the transmission (location-wise) to balance the two sides. The 318 also likes a performance 340 cam, something in the .435-.450 lift range and a duration in the 260-265 range. This will keep the bottom end but still allow it to breathe better than the small stock cams, and still keep from killing gas mileage. Going too big with a 318 is kind of a no-no, since there was never a performance evolution with the 318, they usually have lower compression so unless you do a full teardown, install larger intake valves and a higher compression flat topped piston, the above items/recommendations will still eek out a little more power without compromising its drivability.
 

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The motor has been rebuild in the last five years, fresh motor with low miles. And i dont really plan on doing anything to the heads for now. So the headers dont really help, not worth it? And how do you tell the differences from the 727 and the 904, am not sure what tranny's in it, and what tranny would be better for a mild build?
 

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Go online and look at pan gasket shapes, the 727 has a bump on one edge, the 904 has a pretty square pan. Dual two and a half inch exhaust with the crossover pipe will do everything you want on the street. Headers on the street are a waste in your case, what with stock small valves and with rpm rarely seeing 5000rpm, which is where headers start working over stock dual exhaust, dual exhaust will work more than fine for everything below 5000rpm where you will drive the van. Son't waste the money on headers, do dual exhaust, have it mandrel bent, which is the smoothest bends, don't cut and chop the stock exhaust to make one side, the two halves will be out of sync and the size will probably be different anyhow.
 

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Discussion Starter #5
Well i will have to look at it tomorow, its dark haha, alright il go with duel exhaust. and what tranny would be better to use for a mild build? And i cant find anyone with a 340 were should i look?
 

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Gotta hit the bricks for a 340. They were semi-rare to begin with and kind of hard to come by. You can do the same or better with a more common 360 but there are things that are different from it and the 318 and 360 to stick her behind either transmission. The 904 is a good transmission, stick a shift kit in it and it will be fine for a mild 318.
 

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Discussion Starter #7
thanks for the help. And what if i just buy a comp cam or edelbrock cam with about the same specs of the 340 hp cam? what would a cam like that do to it performance wise like power and would it help me make more rpm?
 

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A Comp 252H, which has stock intake timing, but more exhaust timing and more lift on both, works well to add top end without killing low end. Any "340" cam can be way too much for a 318.
 

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A stock 360 cam will also work, which was very close to the 340 cam. 318 cams are really small, barely breaking .401 lift, some as small as .385lift, so a litlte more helps out , especailly with the small intakes. Anyway, I scanned my first cam profile and I said performance 340 cam, meant to say performance of a stock 340 cam (big difference there), so the profile I wrote in that post are the largest numbers to use safely in an otherwise stock engine.
 

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Discussion Starter #10
alright thanks for the help, what about a edelbrock performance plus cam 270/270 durastion and 420/420 lift? says its for good throttle response and low end torque and thats what i want for the street.
 

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270 is just about right, but don't go any larger without higher compression, bottom end power will drop, so it is good in the sense that you won't be smoking tires, but you will be able to chirp the tires shifting into second gear sometimes.
 

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The only thing i have that chirps is our 03 honda civic, and thats only on slick roads when you floor the gas... (front wheel drive) My 72 3/4 ton D200 doesn't chirp even with the carter AFB and a LA360..
 
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