Cheap 318 performance mods.
I’m new to the Mopar world and was seeking some advice. I bought a 1975 Duster body and a low mileage 318/727 out of a 1977 campervan for it. I was looking for some info on cheap, easy mods to make it run better. I have a set of long tube headers and was considering swapping heads to the newer 302 style 318 head and a thinner head gasket. I planned on using an aluminum intake and 4bbl carb but don’t know what the best intake to use is. Also thought about changing camshafts and wanted some feedback on what would be a good choice. I’d like to stick with the stock torque converter and I’m planning on running a 3.23 rear.
Welcome aboard!
318 Willrun covered it well.
I’ve done a few 318’s over the decades. My advice?
Don’t bother with the 302 heads, use what you have. The 302’s aren’t that good as cast but can be ported out really well. In my opinion, skip porting them UNLESS you can port them yourself! Otherwise I’d just use an aluminum head. You’d be much further along in head flow for power and money invested.
Use .028 thick gaskets.
In the future, head selection can vary. Ether port your own heads and move to 1.88/1.60 valves or spring for aluminum heads.
Any dual plane will do well with the mild modifications planned. Even a OEM cast iron 4bbl. Just use one with the least amount of emissions as possible. In a pecking order…
OEM iron or a Edelbrock Performer will be fine.
Weiand Action Plus or Stealth.
(These lack a coil mounting provision. You’ll need to figure out where to mount your coil.)
RPM- RPM-AG
Carb wise, a 600 AFB or an 650 AVS or equal Holley.
Headers - I very much so highly suggest a set of Summit headers and there 2-1/2 exhaust kit. It requires minor cutting at the tail pipe end, but can run as is.
Cam duration @.050 w/3.23 gears and a stock converter should really not exceed
[email protected]. Use a split duration cam, 4-6*’s split. Grab the matching valve springs and a new timing chain.
Add in a shift improver kit to the transmission & add a cooler with a deep pan. You’ll be set there.
Then move to suspension. Shocks and springs!
ESPO.com for springs. I’m running regular Q1A shocks in all 4 corners.
Enjoy!