swirlport heads

[88dippy]

i have an 88 diplomat w/ 2 bbl, 318, wondering if the engine has swirlport heads on them,is there a way to find out?? im trashing the leanburn w/ a mopar performance electronic ignition w/ orange box....so far this is what i have planned, trash lean burn and replace it w/ performance ignition, get rid of the rediculous feedback carb and replace that w/ a carter afb 625 cfm, also replace intake manifold w/ a edelbrock performer w/ egr and dual exhaust w/ flowmasters or other free flowing muffler....

any suggestions, how are the carter carbs, any headers that will fit an '88 318, im not goin for all out performance but i want a car that can get outta its own way and get decent gas mileage, am i headed in the right direction....

also, how difficult is it to swap out an intake manifold, ive never swapped out a manifold, if i follow the directions should i be fine..please feel free to email me w/ any suggestions you may have or tips for anyone that has done something similiar, thanx

[rumblefish360]

Well, I won't e-mail you, but i'll post till your done.

So far, it sounds good. The intake swap is easy. The Carter is fine. Maybe a little rich to start with out of the box.
Both are straight foward and a snap.
Sorry, I can't help with headers.

[CudaMike]

Unless they have been changed out to something else along the way, yes, they will be the swirl port heads. The 7 digit casting number ends in "302" and you should see it on top of the head when you take a valve cover off.

[Bigfoot]

Just as cudamike said. Another sure fire way is to see if the engine has the rediculous vacuum amplifer on it. Usually on the passengers side there is a black plastic thing that looks like a hockey puck and has 4 or 5 vacuum hoses going to it. If you have one of these abortions than you do not have 302 heads. Since you car is made after 85 you will have 302 heads. 85 year cars can have either depending on where and when they were made. As far as the intake goes I will give you a couple of tips for the installation. I am 6'5" and 300 pounds and for me it was a royal pain to try and work under the hood of a "M" body. I took the hood off and removed the distributor to clear up some room. When I installed the gasket set I first put the two intake gaskets on with a glue called gaskacinch, a small can with a brush applicator on the inside of the top, kind of like contact cement. Aroung the inside of the water passages I used a very small amount of rtv on the heads.I then put the front and rear seals on with the same stuff and then coated the tops of the front and rear with a small amount of rtv. In each corner where the gaskets meet I put lots of rtv probably 1/8" bead. On the intake, I have a engine removal hitch that bolts to the 4 bolt holes where the carb mounts to. I put this on so I could hold the intake with one hand as I guided it down onto the engine. After the bolts all went in I checked with a mirror on the back to make sure it all looked good and that the gaskets had stayed put in the install. This works good for me, it's not a hard job as long as you don't move the intake when you put it down on the gaskets. After firing it up I again checked for leaks at the back of the intake just to be sure. One thing to consider with the edelbrock is if the water inlet is in the correct position if you have a/c on your car. Some are mounted in the middle and a/c won't hook up and some are to the side so you could use a/c. Do the conversion to electronic ignition first to make sure everything is working good before the intake/carb swap.For more tips and lots of help go to Farley's Dodge Diplomat site http://www.dippy.org/main.html and ask questions there. The whole site is nothing but Diplomats.

[George G. Leverette]

The junk yards should be full of donor cars for this swap, try to find a diplomat with the four barrel carb and intake to install on your car.
The ignition from a car without the lean burn will work fine and be a direct bolt in, forget the magazine hype about aluminum intakes and Mopar conversion kits, the orange box is not reliable on a daily driver and costs twice as much as the Wells unit found at most parts houses. Goood luck and keep posting progress.

[Bigfoot]

George reminded me of something. When you do the 4 barrel conversion you have to go to the junk yard and get a throttle mount from a 4 barrel car as well as the tranny kickdown assy. The 4 barrel version sits higher and back farther or forward can't remember, which will hook up your throttle correctly and the kickdown will line up. I totally forgot about this until the time came for the conversion and I hade to modify for about 2 hours to try and get it to work. The next time I was at the yard, I took off the proper linkage and the throttle adapter for 3 bucks. So save yourself the headaches and pick one up. As george said, my first swap was a $100 yard job. Intake came from an 86 Dip. Van's and trucks didn't have leanburn so I took off the vacuum advance Distibutor, thermoquad, ECU and wiring harness. I walked out the front door for 40 bucks and rebuilt the thermoquad for another 25 bucks and a set of gaskets were 35 bucks (intake and valve cover). Some good cleaning and 100 bucks later I was in business other than the throttle linkage problem before mentioned. My gas mileage stayed about the same (as long as I stayed out of the secondaries) but the power jumped. The factory 4 barrels came with 360 heads on them and were rated at 165-170hp. The 2 barrel cars like yours with 302 heads were rated at 140-145hp. After the conversion I did a 1/4 mile run and my unscientific computer program calculated I now had 180-185hp estimated on my weight and 1/4 mile time. Some day I will get around to installing headers and dual exhaust and that should be good for about another 15 or so hp's. This is without cam change or any bottom end work which would jump the hp directly proportionate to how fat your wallet is. Have fun.