I just finished installing a Holley Sniper EFI on my 65. I have been considering doing this since rebuilding my original carb two years ago and still not being able to get things dialed in the way I wanted. I think a lot of the problems I was seeing were due to the previous owner running without the steel plate under the carb for too long, causing corrosion on the base of the carb. Anyway, another big thanks to RockinRiviDad for the post last year, which was invaluable in solving a few issues, particularly the throttle linkage. Here is a bit of a write up with some lessons learned.
It appeared the the tank had never been out of my car, as the original undercoating spray was all over the tank strap mounting bolts, making it impossible to back them off very far since the top is just a lag bolt in a slot. I had to carefully cut through the bolts with a die grinder using a mirror.
I decided to also install an in-tank pump, and as part of doing so also started with a new fuel tank from BestOfferCounts. I chose the returnless Holley Sniper module Part# 19-360. This requires cutting a 3.25" hole in the top of the tank, which I tried to locate in the area near the existing fuel sender hole with the least amount of indentations.
I didn't realize that a vent tube runs all the way and of course the hole saw cut right through that as well.
I looked like I had just shortened the tube by a few inches, and the fuel pump has its own vent, so I just bent the ends out of the way and kept going. The tank depth at this point is 7.25", which is the minimum listed for this pump, but I didn't have any issues with depth. It could probably get another .25" to 0.5" shorter without problems. The instructions for cutting the hanger and pickup tube were terrible. I recommend directly measuring the pickup tube plus pump plus filter sock depth directly, then cutting the metal hanger to match. I test fit this a couple of times, starting longer than necessary, and shortening slowly until the pickup was positioned just above the bottom of the tank.
I re-used the original fuel sender, but only for the guage. I cut off the pickup tube, and the reason I chose to cut the hole on the left side was to avoid the float position. Here is everything ready to go in.
Here is the finished assembly under the car and ready to strap in. I ended up having to drop it back down again to fix a couple of issues after once I got everything else together. The 1/4 NPT fitting on the pump outlet requires thread sealant or it will leak. I used RectorSeal #5 since it was available locally, although Permatex Aviation #3 was also recommended to me. You'll see some foam spacers in the photo that are needed to allow the pump to clear the underbody. These broke the grounding of the tank and the fuel guage. I had to run a direct ground from one of the fuel sender bolts to the chassis to get the fuel guage to work.
The fuel pump wire is run through the trunk and down the channel behind the rear seats and along the door channel through the firewall to the engine bay.
And here it is secured in place with new bolts.
Plumbing the fuel up to the engine bay was the next challenge. Used hard line to -6 AN adapter, and the appropriate barb to -6AN on the short length of hose from the pump to the hard line. I found the hard line to be clean and in good shape, so did not replace it.
I tried the same thing at the front hard line connection, but could not get the adapter to seal due to the short length of line beyond the bead. Instead I simplified and just pushed more hose down past the bead so that it could be clamped on directly. I replaced the old fuel line with the new EFI hose along the stock routing from behind the front wheel and through the frame rail and spring mount. I scraped a few knuckles on that operation because the EFI hose outer diameter is larger than original, but it can be done. I placed the new fuel filter in the stock clamp on the thermostat housing, although it is a little bigger and requires some bending of the clamp. I used the front fuel inlet on the Sniper to keep closer to stock routing, but didn't make the last connection until after flushing the fuel line into a container. If you use the inline fuel pressure guage as I did, make sure to use some thread sealant on the NPT threads there as well. I had a tiny drip that needed to be sealed up.
The plumbing of the vacuum lines was pretty straight forward. Note that there is a plugged port on the front of the Sniper throttle body that can be used to connect the EGR, rather than trying to tee it at the back.
Next was the wiring, which honestly was simpler and smoother than I was expecting. No issues encountered there, although I still have not figured out what to do with the touchscreen inside the car. Just pulled through to the glove box for now.
On to the throttle linkage. Have a look at RockinRiviDad's excellent instructions for modifying the available Holley extension for the throttle rod and kickdown. Here is mine ready to go.
Note the temperature sensor mounted on the back of the driver side head in the above photo. This requires removing the plug with a breaker bar, and using a 1/2 NPT to 3/8 NPT adapter to mount the Sniper sensor. I left the stock temp sensor in the front of the passenger head. The surface temp read a little lower (10F) at the back location with an IR thermometer, but the actual coolant reading on the Sniper was the same as the surface temp at the thermostat.
Next job was mounting the O2 sensor in the exhaust. The Sniper comes with a clamp on O2 bung, but I preferred welding it in, so bought a weld in steel bung, and mounted it on the passenger side. I thought there was enough room in the location I chose, but it proved to be tough to see what I was doing in there. It might be better to mount it a little lower. Anyway, a little work with the welder and a mirror, and it's sealed up, but not pretty.
After that, some wiring clean up and it was ready to go. I could not re-use the stock air cleaner unfortunately, so I bought a cheap open element cleaner. Since I used the front fuel inlet, I also needed to use the Sniper drop base Part# 120-511. I may try to later modify the bottom of the stock air cleaner with that drop base so that I can use it. I will follow up with that if I go ahead with it.
I needed to update the Sniper firmware to be able to run through the startup sequence, but after that it fired right up and idled well. I made all of the recommended idle adjustments, but I'll wait for some nicer weather before I get it out for a drive. If I discover anything else through the tuning process, I'll be sure to update.