Reg Evans

Can anyone here identify the year of 25" Chrysler heads by their casting numbers ? I want to up the compression ratio on my '39 Chrysler 241 and have 3 spare heads here with the following numbers. 869847-1 or 1120806-1 or 1313826-1. I am guessing by the numbers that the one beginning with 13 is the latest of the 3 and maybe has the best CR. Maybe I don't have to have the existing head shaved and could just swap on one of these. Anybody ?

Is there a number on that raised area just above the front freeze plug in your photo. If the engine is original it should start with a T.

Yes, welcome to the forum. My second car as a kid was a red and white 55 Plym station wagon. Loved that car. You might find this one right up your alley even more. www.forwardlook.net/

My '52 1/2 ton has a 3.0 rear end and a 251 Chrysler engine with a 4 speed. I never use 1st unless there's a stump to be pulled. I've never had a problem starting out on a steep hill in second gear. I can cruise on the freeway at 65 all day.

Sometimes a big drink of Marvel Mystery Oil will un-stick the rings. Run it at high RPM while pouring a liberal amount of the stuff down the carb. Then shut it down and let it marinade over night.

I just measured 3 Spitfire heads I have here. I had the gray one milled .050 and it measures 1.902 The rusty one measured 1.850 The blue one measured 1.865 The gray one was powder coated so maybe that coating measures something.

Me too Greg. I also wonder if the torque spec is the same as the larger one.

Well ain't that weird. I took my 11/16" socket around to all my flatties including 3 engines on the floor and all 11 are 11/16" with the exception of the '39 Chrysler.

Hey yeah Ed. I see what you mean. Thanks, I don't feel so alone now.

Thanks Plymouth Road King. This engine runs smooth and has even compression.....90-95 psi in all 6. My plan is to raise the compression ratio some by shaving the head .070. Sure hope these smaller than normal bolts don't snap off.

This is the head on my 39 Chrysler Royal. I've never seen such small head bolts before. They are 1/2" and every other L6 I've seen has 11/16" bolts. Anybody here seen this before ?

Thanks fellers. I will first take a reading with my light meter and then clean all connections and make sure the grounds are good. Then for fun I'll take another reading with my light meter. Hopefully the reading will be much improved. If not then it'll be time for halogens and relays.

Thanks but My '39 Chrysler has reflector and bulb lights. Do they make halogen bulbs ?

I took the '39 Chrysler out for a night time drive last night and was surprised how dim the 6 volt lights are. Besides cleaning every connection involved ,or a new wire harness, is there another trick to get brighter lights. What have you done ? I'd like to stay with 6 volt. Thanks

Looking forward to some photos Jim !

Yeah, that was my guess too.

Thanks guys. A guy on the Chrysler forum found this on eBay so it's on its way to me now. It's Aircraft engine oil SAE 70 just like my manual calls for !!!

I'm going to change the fluids today in my recently purchased 1939 Chrysler Royal with an R7 overdrive and my owners manual recommends SAE No. 70 aircraft engine oil or just SAE No. 70 engine oil. Is this just a single grade non-detergent oil or what ? Why won't regular 80W90 gear lube work .....same stuff that goes in the rear end. Thanks

I converted my truck to 12 volts 18 years ago. The original 6 volt starter has held up perfectly.

Thanks Pete ! I think you're right. How's the Willys doing ?

So, would that be .060 over pistons ?

Thanks Rich ! I don't have the service manual. Can you send via email or via snail mail ?

Just took delivery of a '39 Chrysler Royal Sedan. Love the front styling. I purchased this car through eBay and the owner description was very accurate except he left off the fact that it is equipped with overdrive. I am wondering if the overdirve unit for '39 is different than the later R10 unit. I haven't had a chance to put it on the lift for a visual yet. The owners manual shows that the knob should be pulled all the way out to disengage the OD but this knob does not seem to pull out very much. Maybe 1/2" I don't see any wires going to the carb either. Another question. The car is equipped with a 241.5 engine. I'm wondering if the only difference between a 241 and a 251 is the bore or is it a combo of bore and stroke ? Thanks in advance Guru's

Good news. Nice truck ! I noticed from your last photo that the adjustable rear view arm is missing. I have one if you need it for the cost of postage.

When I got my 52 1/2 ton it had no engine so I installed a Chrysler 251. It's ~2" longer than the original 218 so I shaved the head about .050, moved the radiator forward,installed 2" tabs on the front motor mounts to reach back to the mounting holes, and nipped a bit off the front cross member to clear the oil pan. I also installed a 66 T-Bird rear end w/3.0 ratio so I could keep up with traffic on the freeway. My truck has a 4 speed floor shifter from the factory with granny low and even with the 3.0 rear I don't ever need to use 1st gear.