Some are staggered, some are not. There are bulbs which will fit either way in a dual contact socket - Look at a 1004, or an 1158 to see an example. (I'm not telling you to use those, just explaining why I said what I said). By the way, I mis-spoke about the candlepower of the 1157 - it is only 4 CP on the tail light filament, not 6 CP (if you can tell the difference, I can't hold a candle to you!). Dick Benjamin (who is beginning to stagger too!). ----- Original Message ----- From: "Mark McDonald" <tomswift@xxxxxxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Friday, June 27, 2003 9:39 AM Subject: Re: IML: bulbs for '68 taillights > But Dick, aren't the locking posts on a 2 filament bulb staggered? That is, > not at the same level? I didn't think a 2 filament bulb would seat in a socket > designed for a single. > > Again, hope I'm not boring everybody, just trying to learn something here. > > MM > > Dick Benjamin wrote: > > > Some confusion seems to have crept in here. The two 1157s on each side > > light the 6 watt filament for tail lights, and the 32 watt filament for > > brake/turn lights. When the 32 watt filament is on, you cannot tell > > whether or not the 6 watt filament is on, because the light difference is > > very small. > > > > The inner two bulbs, to have the same brightness as the outer ones when only > > the tail lights are on have to be 6 watt filament bulbs also. > > > > In this case the second filament is not used (on the 68s) so a two filament > > bulb is not required in the center two positions. > > > > Putting a two filament bulb into a single contact socket will usually result > > in both filaments lighting (depending on the particular position of the > > contact button in the socket) which is probably what is wrong with Mark's > > car. > > > > Dick Benjamin > > >