Got in touch with Performance V-Twins in Monroe, NC, and apparently they have a lot of experience modding Vanguard mudmotors. I have a 37EFI PD and asked them what they recommended doing and it seems they don't have any experience with the EFI's yet, but still think that their recipe would be a good fit. Here's what the had to say, let me know what yall think. Seems a little risky without them having EFI experience.

"We created the first modified Big-Block mud motors and have built hundreds of them. The stock cam peaks in torque at 2600 rpm. Our design for your application peaks at 4500 so it will come alive at 3000 and pull hard towards the peak. We add back low end power with a different piston/rod set to increase compression ratio. Milling heads will increase compression ratio but also changes valve train geometry so valve guides will suffer. We do port work on these heads and install Manley Race Master valves and check all surfaces for flatness but do not "deck" for compression increase. Although we have not modified any EFI engines we have modified hundreds of the carbureted engines without changing jetting at all.

I don't deck Vanguard heads to raise c/r. Valve train geometry will be affected, along with manifold mis-alignment. I raise c/r the correct way, with the piston/rod combo. I don't know the EFI system that you have but if it uses a MAF sensor then it should compensate. Optimum AFR for performance applications is 12:1 to 14:1 depending on the application. I instruct customers to read plug color before making jetting changes. A K&N filter will free up airflow as opposed to the stock filter...............on the water a paper filter is not even necessary.

The package that we developed for the mud motor applications 8 years ago has proved its own reliability............again why we don't do the trendy mods that the internet has created like milling heads and installing carbs that are too big for the engine. Our cam profile along with the different rocker ratio is easy on the valve train.

I would be glad to try these mods on a EFI engine, but would also like to know what info the ECM is gathering to run the system. I can't imagine that it would be anything like an automotive system."

There are some guys on here that are close to them. I think its SCmudder7071 . Maybe they will chime in. I have heard good things about them. From what I understand they came up with mudbuddys engine packages.

He did the work on my motor, Great guy very busy , Sometimes it hard to get him on the phone ,but he does good work . When I took my motor down , We talk about 2 hours about motors ..

It be me. I work 5 minutes down the road from Al. He has a proven system for the Vanguards and they work. If you're worried about the EFI, BPS is fixing to release tuners for the EFI. They've got one for a motor with rods/pistons, cam, headwork and exhaust. Buy all the parts from Al and save a ton of money over BPS and then buy tuner. It'll work with that tuner because BPS copied Al back in the day lol.

Al is very knowledgable on vanguards spoke to him over the phone a couple times and bought some parts from him. Would not hesitate to have work done by him. However as he said he likes to raise compression with Pistons/rods not decking heads


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I guess we'd have to get Glade to chime in, but I would think we'd have to have similar C/R and AFR's that match the 3rd kit. Any other factors that would need to be considered?