Looking to order some parts to upgrade when I get home. On my 64 Starfire...headlight bulbs are 5 3/4 right?

 

I believe that is the size you need. These were used in 4 headlight systems.

The "other" round glass unit available would be 7", used on cars with only 2 headlights.

 

Your car would have originally been equipped with Guide T-3 headlamps. Reproductions of those headlamps are available if your car is going to be entered into judging competition. There were three different variations of the 5-3/4" configuration used over the years from 1958 (1957 for some cars) through 1971, after which they were discontinued. Today Wagner is the largest producer of aftermarket headlamps of this size. Most any auto parts store will have them or can get them.

If you want the T-3 replicas they are available from many suppliers specializing in restoration parts. A full set will run around $100.00. A full set of Wagner current production about 60% less.

This is a link to a chart covering all T-3 headlamps from the company manufacturing the replicas.

http://www.lectriclimited.com/images...bulb_chart.pdf