How is the best way to tell if valve covers are low or high script? It is really hard to tell from pictures at times and a lot of sellers don't know what they are. I thought I'd seen the mention of a pennys thickness on a previous post but I can't search and find it. Need a pair for my '58 283ci 245hp 770 heads. Should they be low script 7 fin aluminum and have the cutouts on the top side? My numbers books are on the way. TIA

 

Depends on your VIN - the staggered-hole low-script 7-fin cover was used in '58 up to about #3600, when the molds were changed to the high-script configuration. The low-script is about .030"-.050" high, and the high-script is .125"-.155" high; very obvious difference. All covers had the notches in the upper flange starting in mid-'56. Photos below show both types; low-script on the left, high-script on the right.

 

John, Who does your v/c, they look great. Gary.

 

Thanks for the reply. The difference does stand out on your pictures. And by the way, the ones on the left would work just great and be right nice for my car. My shipping address is .....

 

Jerry MacNeish (www.z28camaro.com) does all of my aluminum work (valve covers, intakes, alternator cases, A.I.R. pump housings, etc.). Here's a better photo of his work on a low-script cover.

 

A friend of mine, who manufactures aircraft components, took a set of staggered, high scrip covers and set them up in a milling machine and milled down the script to the height of low script. PERFECT!!!!! If he hadn't told me, I would not (and still cannot) be able to tell the difference between original low script and his milled low script!

 

They made some 9 fin low script,what motor ( year and horsepower) did they come on?

 

The 9-fin low-script covers (with no notches in the upper flange) were used on 56's through mid-'56, when the notches were added to clear taller runners on the new 3731394 2x4 intake manifold, beginning around S/N 1650. These carried into 1957 production, but when F.I. was introduced, the edge of the air meter interfered with the top fin, and the middle portion of that fin was milled off on F.I. engines to provide clearance, starting around S/N 1900. 2x4 engines continued to use the un-milled 9-fin cover.

The new 7-fin cover (the 9-fin cover with the upper and lower fins removed from the mold) was introduced on F.I. cars around S/N 2900, and on the 2x4 cars around S/N 3900. From S/N 3900 to about S/N 4500, 2x4 cars used both the 9-fin and 7-fin covers, and all 2x4 cars had the 7-fin cover from about S/N 4500 on.