When I decided to fit Fiero seats to my '79 MGB I wanted to avoid drilling the floorpan. This is how I accomplished the task:
[Ed. Note- Fiero seats will not fit the Mark I MGB, but will fit from 1969 onward. Miata seats may fit pre-'69 MGBs]
- I switched the seats so that the Fiero driver's seat became the MGB passenger seat and the Fiero passenger seat became the MGB driver's seat. This placed the seat back recliner mechanism against the transmission tunnel which allows the seat back spring to do its job of raising the seat back to an upright position.
- I discarded the plastic shrouding since there is no room for it in this application.
- Next I removed the runners from the bottom of the seats.
- Next I removed the two rear "feet" from the seat runners and replaced them with a pair of front "feet" from a spare Fiero seat (I stockpiled a few extra seats which I acquired fairly cheaply from several wrecking yards)
- Before fitting these "feet" to the runners, I modified them (bent them) to the appropriate height (to match the profile of the original rear "feet")
- I refitted these modified "feet" in the correct location on the runners. This location can be easily found by using a wooden rail (found under the original MGB seat runners) as a template. The "feet" can be fastened to the runners using self-tapping automotive screws (hex-head), or welding. If you use screws, be careful not to interfere with the movement of the seat in the track.
- The holes in the "feet" were now aligned with the captive nuts on the floor pan in a front to rear direction. However, when the runners were refastened to the seat base I found that the holes required enlargening in a side-to-side direction in order for the bolts to align with the captive nuts.
- When bolting the seat to the floor, I used large flat washers (with a small inside diameter) on the securing bolts.
- I also placed spacers under the front "feet" to raise the seat slightly to provide support under my thighs. These were made from aluminum bar drilled to allow the seat bolt through. Depending on your preference, the spacer can be made to different heights, or you can bend the new rear feet until almost flat to achieve the same result without raising the seat level.
- If you are using the head restraint speakers, the wiring code is as follows:
- Dark Blue is R+
- Light Blue is R-
- Brown is L+
- Yellow is L-
- Remember to get the connector from the donor car when you get your seats
By following these steps your Fiero seats will fit snugly into your MGB, recline properly and fit onto the original floor pan captive nuts. The final touch, of course, is to fit leather seat covers from Mister Mike's!