The stock 340 cam works very well in a 318. A 600 cfm carb,small tube headers with duals,Mopar electronic ign and a good intake(I like the old Holley street dominator) will give you a nice performing car.

I've used sealed power cam CS1019R with good results. Specs are 214-224 duration @ .050, lift is .443int,.466ex, with a 112cl.

Is that a 340 replacement cam? What was the rest of the combination?

Just curious what the gear/converter and such was.

I actually ran a MP 284/0.484" cam in a stock block 318 with 4-bbl and headers. No power below 3,000 RPM, but with gears and a high stall converter it was good at the track. I'm not sure how many modifications and $$$ the original poster wants to invest in?

I'm going to take this in a slightly different direction... I honestly don't think long tube headers are going to make enough of a difference to justify the headache you're going to get. A 1980 Doba uses the traverse T-bar style suspension and Mopar only made one style of bars - it's soft as crap with maybe a 150# spring rate. You WILL scrape the headers along the ground.

There is a really good thread in the race section regarding headers vs manifolds here: https://board.moparts.org/ubbthreads/ubbt...s-included.html

Instead of going with headers use the manifolds with a 2.5" pipe and Dynomax mufflers. Take the cash and put it into the heads. If you're not changing pistons then a closed chamber head of some flavor is what you should use. There never was an LA 340/360 head with closed chambers. This leaves only two options: either rework a set of 302 casting 318 heads, or go with Magnum heads. I really don't think spending the money refitting a 302 head with larger valves isn't worth it. I would go the Magnum route even though there is more to the swap than just bolting them on. They're closed chamber and flow enough to not be a bottle neck on anything under 400 horse power.

FWIW, the pre-1968 273 and 318 had closed chamber heads too.

In 1985, I built a 1970 318 for a friend. It has flat top pistons and the 1967 closed chamber 318 heads (this was advertised as the 9.2:1 compression 318 in 1967), and used the Crower Compu-Pro#31240 cam
"Performance level 2 - Power Compu-Pro - Perfect combination of power and mileage. Provides excellent low end and mid-range power with extended rpm’s for spirited driving.
INT/EXH - Dur @ .050” Lift: 214°/219° RR: 1.5/1.5 Gross Lift: .455”/.474” LSA: 112° RPM: 1500 to 4000
This was a nice combination with stock manifolds and dual 2-1/4" exhaust, 3.55:1 gear and a 2800 stall A-1 converter for the 904 transmission.
With the stock converter and 2.7?:1 gear it was OK, but slow off the line.