I like Cars

Installed the Holley EFI fuel tank module for Camaro and Firebird February of 2023. We wanted something for our LS swapped 1979 Firebird Trans Am. This looked like it would fit the ticket, for the most part it did. I know that Holley has a good reputation and even though it was a fairly significant expense for our very budget build I thought it would be nice not to have a a quiet in tank solution, that was regulated, and fit in the good factory tank we already had.

I would say if you're using a factory tank on an LS swap and you don't have a return style system, or don't plan to use E85 this is ingenious and very well engineered system it will fit perfectly and do the job.

We did have a return style system so it wasn't really necessary to have the in tank regulator but I figured what the heck, a belt and suspenders approach. We got the car going in January of 2024 by April of 2025 the pump had failed I rigged up an external pump and waited on shipping. I was wondering if may be in 2024 they Still used a pump that was not E85 compatible?

We were running flex fuel in our L59 LS. I called Holley tech support. They were really helpful and awesome. Regrettably they verified it is not E85 compatible so don't buy this if you're running E85.

July 2025 we replaced the pump with a $40 E85 compatible pump that had the same provision on the bottom for the sock and it never failed but started making a screaming noise so we replaced it. We were heading on a over 2000 mile trip. I replaced that pump with a $131 AEM pump that was E85 compatible and had the same provision on the bottom for the sock. 4 months later that pump is still in the car. As of yesterday November 2025. we have no fuel pressure. Also the gauge started getting wonky after we replaced the fuel pump the first time, it doesn't read accurately at all now. I am concerned that the regulator has gone bad, or the original submerged connecting tube was also susceptible to E85 and it has failed.

Overall I don't think it was worth the amount of money we paid for it so I would not recommend it just buy an aftermarket tank or run an external pump and a Corvette regulator. Those are also available through Holley.