When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I just bought a 75 F250 ranger XLT with a 390 and A/C but the labels for engine tuning are missing (shocker). Can someone tell me what the factory timing should be?
This was copied from an earlier post I made. By the way, a 4 barrel 390 is not suppose to be an option in 1974, but this truck has an 8/74 manufacture date on the door post. The 4V 390 was an option starting in 1975, supposedly. The VIN does have the "M" engine code, which was not for 1974, but did exist in 1975. I think the new model year for cars and trucks in that era was started in September. I believe this was an non California truck.
This is a lot of initial advance. obviously, it your engine knocks at this setting, retard the timing
I have a 1974 F-250, 4v 390 combo in my truck, also. Here is what the sticker on the valve cover says: 390 cid July 1974, Spark plug BRF-42, Gap .032-.036, point gap .017, dwell 24-30 degrees. Timing 16 degrees BTDC, Vacuum hose disconnected and plugged, at idle, 650 rpm in drive, CO 1% max.
__________________
Reply With Quote