470 oil pressure sending units

[blkzoe]

Installed new oil pressure gauges and sending units for my 470's to match my recent rebuilds. Oil pressure has always been a crap shoot w/ 470's so I'm a little OCD about it. Installed new Sierra sending units after taking readings off mechanical oil pressure gauges[FONT=helvetica, arial, verdana, sans-serif] (both were 60 lbs. at cold startup; 40 lbs. at hot running @ 3200 rpm). With the Sierra gauges I had a 20 lb. differential at cold start and a 40 lb. differential at hot idle! I could just scream. Remove/replace the low reading sending unit w/ another new Sierra, and now both engines match hot and cold pressures.

Has anybody else had this issue w/ Sierra ([/FONT]18-5899)[FONT=helvetica, arial, verdana, sans-serif]? Are the redesigned $60 Mercruiser sending units ([/FONT]8M0068784)[FONT=helvetica, arial, verdana, sans-serif] that much better?

BTW, no lifter noises and running temps can barely exceed 160 degrees.[/FONT]