The following build upswill give you a good performing street engine and is NOT intended to be the ultimate build up of a 273-318, nor is it the only streetable combination.
Package components:
Source: MP
All the following parts can be purchased from an MP dealer or any CC dealership. For an intake I recommend the M1 dual plane intake. A note of caution is applicable here. If you are running a 79 or later AC system, rotary compressor, then the water outlet will interfere with the AC compressor. To the best of my knowlege there is no easy fix for this. For a cam I recommend either the production 360 4bbl cam or the 340 Magnum reproduction cam. Don't forget to add the correct valve springs. Advancing the stock 2 bbl or 360 4bbl cam 4 degrees will help the low end and is recommended. You can do this with either the MP key way kit or the MP timing chain set. Adding the MP electronic ignition package is a very good idea as well.
Source: Edelbrock
Intake recommendations are the Edelbrock Performer, either with EGR or without depending on year of car. The matching Edelbrock cam and valve springs are a wise investment. Advancing this cam 4 degrees is not recommended, later factory cams where ground with a built in retard that lessen emissions and performance. This intake will clear both the RV-2 and the C-171 style compressors which means it is useable in any year Mopar. Although Edelbrock claims the intake only fits to 85, I called them on it and their claim was that it would not fitt roller cam engines. This is not true so you can use this intake on any non-Magnum engine. Addition of the MP electronic ignition kit is a wise idea as well.
Source: Boneyard
Intake recommendations are for any stock 4bbl intake. In 79 there was a change over in water outlet design to clear the new C-171, rotary style, compressor so keep this in mind when looking for an intake. Again, the later style intake will work with the RV-2 compressor but not vice versa. You can run your stock cam if you wish to save a few dollars but a steel timing set, Summit's house brand adjustable timing chain set is an inexpensive and suitable choice, and advancing the stock cam 4 degrees is wise. Running the MP electronic ignition kit is a wise idea.
Generic comments:
If your MoPar is already equipped with non-LeanBurn electronic ignition you can recurve your stock distributor with the MP recurve kit and run the Orange box instead of springing for the entire kit, this assumes your distributor is in good shape. Exhaust recommendations are for a dual exhaust if emission restraints allow. Running 340 Magnum exhaust manifolds can be considered If one wishes to avoid the hassles of headers and can fit them in the chassis. Headers can be run if you wish but for a streetable package keep them small, 1 1/2" or 1 5/8" primaries recommended. There are block hugger, center dump, shorty style headers out there that clear on the passenger's side but I am not sure if the driver's side will clear the power steering gearbox, if anyone knows please feel free to email me. For those of you stuck with a single exhaust and catalytic converter package I recommend running 2 1/4" headpipes y'ing into a Flowmaster dual 2 1/4" in, 3" out Y pipe and a 3" system from the Y pipe, through a new high flow 3" converter out to the tailpipe, assuming space is available. For air cleaning I recommend a K&N filter. I am also impressed with their stubstack airflow straightener. Adding a fresh air pick up is wise, under hood air is hot, so any cold air you can provide the engine will help. Later models required to keep their stock parts for emissions purposes can run a stubstack inside the stock air cleaner, along with a K&N filter and should have factory fresh air in place, make sure it works. I won't go into tuneups but make sure all your parts are in good shape, cap and rotor, plugs and wires, etc. Don't run 20w50 oil unless there is a real need for it. The thicker the oil the more HP it takes to pump it, and the more HP it consumes as windage. Adding a windage tray is a good bet if your going to open the pan. HV/HP oil pumps should not be used unless your running wider than stock bearing clearances. A 650cfm carb is as large as I would go on these engines.
© 1999 Steve M. Knickerbocker