This thread is of considerable interest to me - I have as yet been unable to obtain any previous maintenance records for my '68 Crown other than the few receipts that "came with" in the glove box. The car does run splendidly with nary a ping on 89 octane gas, though, so I suspect the engine has been through an overhaul once in its life - mileage is now just over 114,000. I try to drive her once a week on my commute of about 75 miles round-trip freeway miles, and she really rolls when you "turn the horses loose", having great compression and engine braking and tons of 440 power. Did the dealers do a "warranty" change to these cars when the fuel changes took place, or was the timing such that it was strictly after market rebuilding? Did they actuall retime or recam to obtain a lesser compression ratio, or was it just the hardened valve seats thing I have heard about? I have excellent reason to believe this car was mostly dealer maintained, at least through the warranty period - the a/c has also been updated, but not by the selling dealership. The abundance of OEM parts makes me think it was only after the original owner died and the car "passed down" to people with less appreciation for her that things began to get iffy on maintenance. Thank goodness I got her before she slid too far in condition! Say Ken, where are you and your '68 located? I have yet to see another Imperial of any year on the road in my area, though I know from the list that there are a few! Waiting for summer?? Kate Justet Triplett Kate's Custom Gunleather Monroe, Washington Proudly a member of NRA and owner of "Lucille" 1968 Imperial Crown 4-door HT >Date: Thu, 04 Dec 2003 09:20:22 -0800 >From: Ken & Tracie <Subject: IML: Compression Ratio & Rebuilding >Reply-To: mailing-list@xxxxxxxxxxxxxxxx >Hello All, >I would appreciate your opinions, thoughts and experiences with rebuilding a >>late 1960s 440 for use with today's gasoline. >I plan to go with the necessary modifications to accommodate unleaded >gasoline. >But what about the compression ratio? Will the currently available >91 octane >"premium" grade work in a '68 or '69 440 rebuilt to stock >specifications? Or >should I have my machinist take the steps required to drop >the compression >ratio to 9:1? I know about the tricks such as retarding the >timing or using a >water injection system. But I also know that some older >engines can be modified >with different distributor advance curves and/or cam >shafts with different lift >and duration specs to allow older engines to >retain their original performance <characteristics with a lower compression ratio. >Thanks in advance for any replies. <Ken Josephson <'68 Crown Four Door Hardtop