Originally Posted by 1970s Titans
The GVWR on this one is 11,000. But I'm not doing any sort of real engine mods on it. I kind of like it the way it is for now and I can't afford any expensive parts quite yet. For now all I'm doing is getting the burnt valves fixed and maybe upgrading the exhaust
Most likely those early heads on your rig dose not have hardened valve seats. Do the job once!
Installing the 302 heads will up the compression. More compression helps! The can be purchased from Rock Auto for far less than any local machine shop ($550.~$700.) can do a complete valve job to your heads, this will save money for other upgrades!!!
These heads you are looking for; "https://www.rockauto.com/en/catalog/dodge,1985,b350,5.2l+318cid+v8,1075889,engine,cyli nder+head,5304", purchase the #302 casting ONLY!! Using a Felpro gasket set the engine will still run on unleaded fuel.
Adding a four barrel manifold with a Demon 1901 VACUUM secondary carb will keep the rig from bogging down on hills AND if you keep your foot out of it better fuel mileage than any stock 2 barrel carb.
Timing chain is most likely bad and a single row chain at that. Installing a double row true roller timing chain (Summit SUM-G6603R-9) & advancing it 2 deg (cam timing was retarded for smog reasons from the manufacture).
Check your ignition system! If it has points upgrade to a later mid 1970's B300 318/360 distributor.
Check the outlet size of your exhaust manifolds, if the are 2 1/4 they are the HD manifolds. If not get a set from a latter 1970's 360 truck / van engine or get headers. Headers are cheap, anything will bolt up to that engine with all the room around it. Use 2 1/4 pipe to muffler and 3" outlet for single exhaust or 2 1/2 / 2 3/4 out let for dual exhaust.
Set the timing for a total mechanical advance of 35 degs and adjust the vacuum advance at 3000 RPM's to 50 degs MAX-Total advance.
Check the fan installed if it has 5 blades upgrade to a 7 blade fan it will cool better and If it dose not have a viscous fan clutch install one! This alone free's up 15~20 HP!
You will love this combination I suggested. This is not a Hot Rod setup! It will in fact free up about 100 HP, make the engine more efficient and better fuel mileage. I have set up many 318's this way for years!! I do have a Edelbrock 4 barrel manifold if you are interested. PM me if you like more info..