Bulkhead or grommet???

I am relocating the TCM to inside the cab. The TCM will mounted under the driver seat. I would like the harness to exit the cab floor and go directly to the transmission. I am not sure what the best option would be grommet or bulkhead???? If using a grommet is the better option, I would like a 90 degree molded grommet. But I have had no luck finding a 90 degree or even an odd angled grommet. The reason I am relocating is the company I am using for tuning prefers the TCM inside the cab. Any ideas of a better way I am open.

I think the method depends on how much you're looking to invest in the harness and how durable or sealed it needs to be. A club or motorsport harness with bulkhead will offer more of a seal than a grommet, but perhaps a grommet is sufficient for what you're doing.

I've never heard of this brand, but they seem to make a combination sealed grommet/90 degree boot, which leads me to believe you may be able to find them from other vendors as well.

http://www.elastomerrubber.com/sale-12711358-wiring-loom-90-degree-rubber-dust-boot-automotive-firewall-grommets.html

Thank you! I wasn’t sure what the best would be. If this was your daily vehicle with your knowledge/experience what would be the better option as far as longevity with the daily abuse?

OEM harnesses often go through firewalls and sheetmetal grommets with boots like this and it generally works for them, so I think done right you should be fine.