The Chrysler 318 has a somewhat bad reputation when it comes to performance, but that doesn’t have to be the case. There are plenty of options for the 318 that’ll get it going in a hurry with plenty of power. This article is aimed at the LA 318 as opposed to the poly, but all the advice will still work with either engine.
The first method to get more horsepower out of your MOPAR 318 is to slap on a four-barrel carburetor. There is no need to go nutty here, either; a 600 or 650 cfm unit will work wonders. I put the Edelbrock Performer intake on my ’68 318, along with a Holley carb and it not only gave me a few more ponies, but it ran smoother all throughout the RPM band.
This mod has been tried and true since the beginning of headers. When coupled with the four-barrel, headers can really free up some robbed power. Of course, as with anything, the more you spend the more you get, but even a set of cheapies will improve performance. Doug Thorleys are nice, but a pair from Summit or JEGS will do the trick nicely.
Adding a street cam to your Chrysler 318 is a sure-fire way to beef up its power. As with the carburetor, you don’t want to go crazy with the cam unless you are building a race-only engine. A mild cam is great for the street and you’ll feel the added power, there is no doubt.
The 318 is known for having anemic heads. Slapping on a port and polish job will vastly increase its power. Add in 1.88/1.60 valves and you will have a screamer. The other option is to source a set of heads from a small block 360 MOPAR. The 360 heads already have nice ports and valves. The only thing you’ll have to do is shave the surface thirty-thousandths of an inch to bring compression back up to a workable level.
I ditched the stock engine-driven fan on my ’68 and replaced it with an electric fan and saw quite a bit of power from the simple mod. The engine no longer has to work to spin the fan, which frees up horses. Just do a little research to be sure you are getting a fan that’ll move enough air for the V8 radiator.
I hope these tips help move you in a direction to upgrade the 318 instead of ditching it for a 360. Both engines are great, but it’s a lot of fun to have a little ‘sleeper’ 318 that’ll blow the 350 guys away at the stoplights.