1969 road runner 383 4 speed

[todd8525]

customer dropped off a 383 roadrunner to change plugs n wires.the plugs are v-power stock number 5858. which according to different
supplyers are correct for this car but... they resemble a lawnmower plug and are a bitch to start.(the ones removed are not for this car.

[todd8525]

81484

[72BBSwinger]

BB Mopars use a 3/8" reach plug just like that.

[todd8525]

i got that but they use a 13/16 socket and destroy the washer.the shoulder dont seem to go by the head casting

[72BBSwinger]

Stock iron heads? Should be a no brainer unless the seat in the head has something wrong from using the wrong plugs before or the old washer is still there?

[todd8525]

bought a set of champion yr15's and seem to work fine.all parts supplyers list the 13/16 plugs.i put a mirror and inspected it ,put a camera in to inspect the treads and?and yes they are stock cast heads.is thier another set of heads incase somone has swapped the heads out over the years?the car is a plain model.im at a loss,the motor was pulled in my garage and rebuilt by a friend and all part numbers matched the 383 1969 era?the plugs i took out are a 5/8 shank and match the plugs i replaced.is thier a 5/8 shank plug for these motors i should be using?are the plugs i have in the motor going to ruin the motor?the owner is a really good friend of mine,ive been a big part of the cars finding and restoration.A set of plugs are basic.im starting to feel like a real ass hear.

[72BBSwinger]

I have stock iron heads still on my current engine. All the plugs I've ever used were 13/16" and I've had nor heard of a problem with any interference issues. It is normal and expected for the washers to crush to flat when tightened. I've ran Autolite 72 and 75 and am currently running some NGK's. I don't see how you could've hurt the head by pulling out the plugs so if there is something wrong it was already. The BB Mopar wedge is probably the easiest and simplest designs in history to work on. Can't believe you can't just thread in the spark plugs unless for some reason somewhere along the line someo.e changed the threads?

[todd8525]

i got the car in on a unrelated issue,(replacing some chrome trim with new).the owner has gone out of town so i bought him some header gaskets and pulled the headers for kicks.the washers are suppose to fit in a (round slot) to crush the washer flat and seal the plug to the head.got that.the heads are not damaged,the threads are stock and everything seems fine.the washers are being crushed past the shoulder.what i mean by that is you have threads,washer,than the shoulder of plug.than the 13/16" than the porcelin...
the washers wont fit into the round slot and are being pushed upwards past the shoulder.the slot doesnt seem large enough for the washers to fit into.now ive borrowed a buddy and we pulled the plugs out of his 1969 440 6 pac (unrestored) road runner.same thing! so he cut the washers off and added some brass (indexing) washers and voila!now dont that make you scratch your head?

[72BBSwinger]

All I can say is I've never used a set of 906 heads,which both 69's would have, and have never heard of such a thing. All the plugs sitting on top of my tool box do not have washer protruding past the bodies before or after they're crushed. A Champion rj12yc is the plug that is considered the go to plug for a BB block Mope btw. Glad you got the back together.

[todd8525]

81828well ta da! found the problem.bottom end is numbers matching but are not the 906 open chamber heads.we traced the cars history.the engine in the 80's was over heated by one of the previous owners and the heads wear swapped out for 71 or so heads likely from a 400.the owner that the was purchaced from has been reading to many magazines (not 906 heads).i trust the local mopar nut.and the block and bottom end are original but the heads wear swapped out by the cars second owner in the late 80's.-
the local car nut was gutting a true 440 4 speed car that was lost to a previous owners neglect.the poor thing was rotten beyond repair but will donate its parts to complete anouther car.this guys collection would make you...well? 69 440 6 pac 4 speed unrestored.a 69 440 rt charger(light blue white top and interior) a 68 super bee,a 440 6 pac coffee tabel,and a 69 sport sattelight in sad condition.
the large plug washers wear the ngk v groove the right plugs are the champion rv15yca's.after a burger king meal gord (mopar nut) swapped the carb out for one of his, turned a few screws and tinkered for twenty minutes and now the car performs like no tomorrow,i think we could make the owner cry tears of joy.
now this before the new door decals,emblems,and painted the hood grills the proper colours.(the pic swows the car a brighter yellow than it actually is).

[72BBSwinger]

One thing I have found out since this post is by golly they had an oddball Motorhome head that used bigger water jackets around the exhaust ports and spark plugs. These heads actually used a no-washer, tapered seat plug that no other Mopars used. This sounds exactly like what your experiencing or already figured out. So if the plug numbers you used are for a 79 440 Winnebago, you're good lol.

[todd8525]

81962
eh over the winter im swapping the heads for the owner.hear is the 440 6 pac 4 speed car,and yes he has the weather checked red wall tires and dog dish caps

[72BBSwinger]

A post car! My favorite, pop out quarter windows saved quite a bit of weight.