• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Cam for a 68 318

68Coronet500!

Well-Known Member
Local time
8:11 AM
Joined
Feb 2, 2021
Messages
50
Reaction score
18
Location
Southern California
I'm looking to upgrade my 318 and currently have a performer intake, 4bbl carb, hooker headers & exhaust, and am looking for some guidance. I'm thinking the cam should be first priority and then possibly the gearing in the rear end as it is currently low and I want a lot more power out of it.

Any suggestions? Also, when I'm having that done, anything else I should be looking at?
 
For that 318 I'd recommend a the Summit K6900 Camshaft Kit and Cloyes Timing Chain/Gears. For the rear axle ratio I would go with 3.23s or a 3.55 ratio.
 
The stock 318 cam is pretty small, I think less than 200 duration @ 0.050"
You can cam it up a bit, like around 210 @ 0.050" and get by with the stock torque converter. You will want to re-curve the distributor also for more initial timing.
With more that the approx 210 @ 0.050" duration, the engine will respond much better with a high stall torque converter.
The Summit K6900 mentioned above would be a good inexpensive choice.
 
I'm looking to upgrade my 318 and currently have a performer intake, 4bbl carb, hooker headers & exhaust, and am looking for some guidance. I'm thinking the cam should be first priority and then possibly the gearing in the rear end as it is currently low and I want a lot more power out of it.

Any suggestions? Also, when I'm having that done, anything else I should be looking at?
You might find some good reading here: Search Results for Query: 318 cam | For A Bodies Only Mopar Forum
 
Back in the day, I built a 360 for my tow vehicle, '76 van. I used a Comp High Energy hydraulic. Worked really great. Good gas mileage and all the torque and power I wanted. Something similar would really help a 318.
 
I would make a gear change before the cam change.

We have done quite a few different cams in stock 318s with a 4 bbl and headers. They love smaller tight LSA single pattern cams like the hi energy cam that was mention in the above post. The summit 6900 works well also, i think I would generally pick the hi energy single pattern over the 6900 though in a 318. For 318s we have quite a bit of experience running the Melling 23203 which is the next step up over that summit 6900, 214, 224 @ .050”, it is as large as I would go. I was more impressed with it than the 340 OEM cam. It has a decent lope at idle, we would shift it at 5500. That combo we ran a very very nice 904 with a shift kit and 3.23 gears. With the 3.23s it ran low 15s 1/4 mile E/T with the stock converter which consistently stalled to 2200 rpm. There was a LOT of performance left though with more converter, it doesn’t come on hard until 4000. We used 340 valve springs on all those, even turbocharged 2 of those engines with the Melling 214, 224 grind in 318s. Between the turbo engines and the tweaking we did N/A we had a lot of fun with that combo though, even ran 4.10 gears once. It has good top end even with deep gears, I ran 6700 rpm for 4 miles once in top gear with the 4.10s My brother (curiousyellow71) and a friend where driving the car back from a Friday night drag race and they made it to 6200 rpm in top gear with 3.23s in a 72 Satelite. Lol, down a bit of a long hill, but still 150 mph is pretty impressive out of a 318 in a b body. :) It didn’t set the world on fire for quick E/T’s in the quarter mile, 15s isn’t bad for what it was, but it sure was fun on the open road.

Still. with a stock converter, 4 bbl and headers and 2.73 gears, thru the 1/4 mile we found that the stock cam was about as quick as any of the other cams. That is why I would do the gear swap first.
 
Last edited:
68Coronet, your post didn't say what rear gear ratio you have. I hope it's a 3.23. The quickest improvement you could make is a quality 10" torque convertor. It will make a ton of difference, more than a cam change. Cam can follow.
 
I'm going to assume here but, I believe your goal is just to have a nice cruiser correct? The other part of this equation is where you cruise will you be driving more city miles (aka stop and go, heavy traffic) or lot's of highway without much stopping?
 
After rebuild on my poly, headers, cam, solid lifters, ed, TC, among other things, I swapped to 3:55's having 3:23's. Wish I left that be. Cruising RPM is irritating at 65-70. Didn't find any more noticeable giddy-up off the line...granted, I have a possible issue with the timing currently running it full-mech; but runs like a top until such time I can dig into this.
 
There is no "magic camshaft" .
 
I did the Summit K6901 in a 68 273 Valiant that worked very well. Edelbrock Performer intake and 600 Edelbrock AFB.
Along with TTI shorty headers and their complete dual exhaust. Worked for me.
My 63 Belvedere has 1970 318 and I used the Comp Cams CRS 268H-10 Headers,duals,same Performer intake and 600 carb.
Sounds good, runs well for a stock bore,heads and pistons 318.
 
I'm in the same scenario. I have read alot about hughes whiplash cam and listened to some youtube videos. It's designed to work in a bone stock 318. Not sure if it's the way to go but I sure like the sound of it.
 
I'm in the same scenario. I have read alot about hughes whiplash cam and listened to some youtube videos. It's designed to work in a bone stock 318. Not sure if it's the way to go but I sure like the sound of it.
 
i never gave **** what the cam sounded like, just how it moved the car. Small block cam selection seems even more complicated than BB.
 
Auto Transport Service
Back
Top