I’ve got the Mikuni replacement kit from Vintage Performance Developments in New York, and have just started on the process of removing the old Strombergs from my 71 Plus 2. This is the most mechanically adventurous things I’ve yet done on the car, so wish me luck! Unlike most people on this forum, I’m new to working on cars, so I’m taking it slowly and just going step by step.
I have no experience of this swap but you may find it informative to see Oliver Naylors YouTube video adventures when he chose to swap his over.
Regards
Richard
Yep have watched those He had issues getting them to run right due to some not so great work by an earlier mechanic. Hoping it will go more smoothly for me!
Just as a matter of interest, what has prompted you to replace your Strombergs?
The Strombergs have always leaked oil quite a bit (despite attempts to fix) and I haven’t been able to not get them to run overly rich. But more so the Mikunis should have more power and better responsiveness. I thought about going the EFI route, but wanted to stay with carbs.
Check the seal area between the rubber Mikuni mount and the Stromberg adapter plate carefully. I used some engineers blue to check where the seal contacted. The notched cutout in the adapter is very close to the raised seal ring on the rubber mount. I had a leak there and ended up clocking the rubber mounts. It was still very close but sealed.
I have a S4, so this might not apply to a +2, and had to slot the engine mount to get the carbs to fit between the footwell and bonnet.

Check the seal area between the rubber Mikuni mount and the Stromberg adapter plate carefully. I used some engineers blue to check where the seal contacted. The notched cutout in the adapter is very close to the raised seal ring on the rubber mount. I had a leak there and ended up clocking the rubber mounts. It was still very close but sealed.
I have a S4, so this might not apply to a +2, and had to slot the engine mount to get the carbs to fit between the footwell and bonnet.
Thanks Scott. I also was a bit concerned about how close that notch got to the edge of the rubber. I’ve put some gasket in there, thinking that would help with the seal.
Not sure if I follow your second point, but on the +2 with its hood/bonnet hump there’s better clearance than with the Strombergs. The plastic cap on the front Stromberg actually contacted the underside of the hood! So this will solve that issue at least.
Richard
I posted an article on the site several years ago titled, “Mikunis In, Strombergs Out” with some pictures of my installation and praise for the extra power the Mikunis offer due to their greater air flow. Ken Gray at Dave Bean Engineering helped me with the installation.
Lee
Thanks Lee, yes your thread was one I read carefully and gave me the inspiration to go this route!
I’ve been stalled on it as weather has been too cold and I’ve had some travel, but hoping to get back to it in the next couple of weeks.
Richard,
Let me know if I can help if you have a problem with the install when you resume work. If I can’t help you we’ll get Ken Gray involved. One clever thing Ken did for me was make it possible for me to attach the OE air box to the collars supplied with the VPD kit. If you want to use the OE box instead of fitting K&N filters I can explain how to do that.
You’re going to be very glad you chose this path to replace the Strombergs. I know of two other Plus 2s in California who have installed the Mikunis and praise them.
Lee