Source for a stock camshaft kit 383

[Billccm]

The car has always idled rough and been cold natured. When I first looked at it the previous owner told me he never liked the cam.

Car has great power. Goes down the road smooth as silk. Even gets good gas mileage. Idles like it's trying to come apart. Compression is lower on 7 & 8, but leak down shows no issues. Never smokes. Great oil pressure and no knocks or ticks.

Local shop thinks a cam swap is a good first step. I'm willing to take the gamble.

Thanks for the feedback and advice.

 

[lewtot184]

Any comments opinions on these items?

View attachment 1965156

these parts should be an improvement. if you look at the specs summit provides this cam is identical to a magnum cam. the 050" on duration numbers match OEM. it has the 115lsa, lift is the same as OEM. the 302/324 number includes the ramps and should be ignored. summit specs do state to limit valve spring pressure to 280psi; don't ignore this. the only down side is with a low compression engine and this cam is with the late intake valve closing it may not build enough cylinder pressure for a tire fryer. i have a friend who used a stock magnum cam with a 8:1 piston 383 and it blew 130psi cylinder pressure. car drove nice but didn't make as good low end torque as i would have wanted. on the up-tick i did buy one of these while back for a spare, so i don't think they're bad. the 6400 cam will close the intake valve 8-10 degrees sooner and that will help build more cylinder pressure. the 6400 has specs nearly identical to OEM magnum, but a tight lsa at 112. i put one of these in a 9:1 compression 4spd '69 super bee and was pleased at how nice it ran. either of the two comp cams i listed will improve cylinder pressure. i probably wouldn't buy anything until i got things apart and know exactly what i have and what my starting point is going to be.

to confuse matters more i found a couple more likely candidates. a howard's magnum replacement 720031-12 would work. i'd like to have one of these for a 6pak project but can't seem to find one. a speed-pro kc1148r looks to be a copy of the old mopar 272/.455 cam. the 272 is an overachiever in my book. i've actually thought having a custom comp cams ground with their 276/.464 lobe for my 6pak project. i've got so many cams laying around now it's nuts to buy another,..lol!

 

[Don Frelier]

Hard to beat the .455 cam in a good 383 setup.
I'm thinking of putting one in my Plymouth this summer.

 

[PRHeads]

i probably wouldn't buy anything until i got things apart and know exactly what i have and what my starting point is going to be.

Great advice!