Cat Whisker Posted March 16, 2020 Report Share Posted March 16, 2020 This has to be by far the best group for working/rebuilding classic Chrysler products. I hope I'm not becoming a PITA asking all these questions but here's a few more. 1. So far no problem with freeze plugs for the water jacket. The Dorman 550-023 (steel concave 1-5/8) plugs fit perfect. Does anyone have a part number for the camshaft freeze/welch plug that's 1-3/8 inch and the 1-3/16 plug in the head above the temp sender?? 2. If need be, I have valve seat cutters and stones however my valve seats look to be mostly OK but has anyone had any experience installing new hardened ones and is that even recommended?? 3. If so, does anyone have a part number for hardened intake and exhaust ones that are recommended?? 4. The cylinder head looks to be in great shape. That was after I was able to get over a foot of steel wire (left by the factory) out of the water passages. My old Starrett straight edge shows it's flat within .0015 all the way. This tells me that it might of already been shaved. Is there any way to tell (some thickness measurement) if my 23 inch head has been shaved already or do I need to cc the chambers?? 5. I'm thinking also of having the top block milled off about .010 just to clean it up, especially around the head bolt/water passages holes that have some pitting. I know I will need to check valve clearance after I find out if the head has been shaved. What are the pros and cons for doing this?? I could probably search and find some of the answers but getting the correct ones from folks in this super group that have the experience is worth more than I can express. Again many thanks for all the assistance. There's no way I would of attempted to tackle this without finding this group first. Quote Link to comment Share on other sites More sharing options...
JBNeal Posted March 16, 2020 Report Share Posted March 16, 2020 (edited) When in doubt, cc your chambers before ya get started to verify your baseline measurements...then you have a better idea of what options are available to ya...shooting for 8:1 CR should give ya decent power, though 9:1 might be pushing it...another reason to shoot for 8:1 is to leave ya some wiggle room in case the head needs to be milled somewhere down the line...cleaning up the top of the block isn't a bad idea, and good to follow through on valve measurements...don't forget about them pistons, tho Edited March 16, 2020 by JBNeal 1 Quote Link to comment Share on other sites More sharing options...
Cat Whisker Posted March 16, 2020 Author Report Share Posted March 16, 2020 Thanks JBNeal, I will cc the head as I don't think there is any reference point to measure from for thickness. I'll talk to the machine shop and see what point(s) they use to for milling heads. Ending up with 8:1 is about what I'm after. Once I get off my butt and measure some more, quench, valves, pistons, etc, and get the head cc'ed, I'll have a better idea of how to proceed. Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted March 16, 2020 Report Share Posted March 16, 2020 Valve seats should already be hardened. If they're in good condition just touch them up, along with the valves, lap 'em in, and run it. Quote Link to comment Share on other sites More sharing options...
greg g Posted March 16, 2020 Report Share Posted March 16, 2020 Seems if you measure the head from one of the edge head bolt flat spots to the underside of the head, stock is nominally 2 inches. If it is substantially less you are probably looking at a fiddled with head. I did .040 off the head, 010 of the block, and an using a one piece solid copper head gasket that is a marine use piece. Using stock cam runs great on 87 octane. Has lots of grunt. 1 Quote Link to comment Share on other sites More sharing options...
Worden18 Posted March 17, 2020 Report Share Posted March 17, 2020 4 hours ago, Merle Coggins said: Valve seats should already be hardened. If they're in good condition just touch them up, along with the valves, lap 'em in, and run it. I'll second what Merle has stated. We found out to my surprise the seats on my 51 230 were hardened (learn something new everyday) and my builder touched them up during the rebuild. Quote Link to comment Share on other sites More sharing options...
Sniper Posted March 17, 2020 Report Share Posted March 17, 2020 Odds are more likely the guides need replaced than the seats need replaced. Quote Link to comment Share on other sites More sharing options...
Cat Whisker Posted March 17, 2020 Author Report Share Posted March 17, 2020 Thanks Sniper. I'm going replace the guides since i'm already in there and because someone has already replaced them, the wrong way. At least half are wrong. They are all in ordinated the same way, and I think I saw in one of my manuals, the exhaust goes in, big (counter bored) end up and intakes go the other way. Thanks Merle and Wordenn18. You two make it easier. I just gonna clean them up and lap em a bit. Thanks again. Thanks greg g. If in fact the head was from a 2 inch casting, then it has been shaved .029 to .032 so I'm guessing somebody took of .030. Would of been nice if they would of stamped that somewhere. My machine shop guy says they index the head for milling off the machined flat boss area for the thermostat/water elbow. I can see why because that area gave me the most consistent readings. Thanks again. For all: I did find the correct freeze plugs. Melling makes the concave ones with part #'s MEP-21 (1-3/16 above thermostat) and MEP-12 (1-3/8 rear cam plug). 1 Quote Link to comment Share on other sites More sharing options...
Sniper Posted March 17, 2020 Report Share Posted March 17, 2020 Thank you for the part numbers. Too many times people say they find something that works but leave out part numbers and the description is vague enough that finding what they actually used is tough. 1 Quote Link to comment Share on other sites More sharing options...
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