• To ALL forum users - As of late I have been getting quite a few private messages with questions about build ups here on the forum, or tech questions about your personal project. While I appreciate the interest, sending me a private message about these topics distracts from, and undermines the purpose of having a forum here. During the day I wear many hats as a small business owner-operator and I work tirelessly to provide the absolute best service possible to you, our valued customer. When I created this forum I rounded up some of the best minds I knew so that any tech question you might have could be asked and answered by either myself or one of my highly experienced moderators, this way the next time this same question is asked the answer can be easily found and utilized by the next IH enthusiast having the same question. This allows me the freedom to run the day to day operations of the business and minimize the impact to shipments and shop activities that these distractions can cause. It is of the up most importance for me to complete the daily tasks in order to best take care of you our customer, all the while providing you a forum to get the level advice and input you have come to expect and deserve from the premier IH shop in the country.

    So with that I ask that anyone with a question about one of our build ups or a general tech question to please use the forum as it was intended. I am absolutely available by telephone to answer your questions as well but at times may direct you back to our website to better field your question or questions. Most other private messages I will be glad to answer for you.

    Thank you for your understanding.

    Jeff Ismail

73 Cummins Conversion Questions


New member
I was looking to buy a Scout and do a cummins conversion, however I found a converted 73 with a 4bt. The fuel pump is the bosch rotary style. The pump is a weak link if I want to increase power. The rig is $15,000. Good body, minimal rust, frame off restoration a few years ago, 4" rancho lift, new tires, seems to run well. Both the motor and transmission are in excellent condition.

I would prefer the 4bt with a p7100, a conversion of the rotary isn't worth the trouble in my opinion and I can live with it as is... For a while.

I'd like to ask if anyone has experience with the 4bt in a Scout, rotary or p7100?

What can I expect from the performance of a stock rotary?

If you have any suggestions concerning the two?

I'm open to buying a conversion with the 4bt p7100 if anyone knows of one?

I'm open to buying a Scout (71-76) with a clean, straight, rust free body and dropping a 4bt into it... However it seems this rig will save a lot of work.

The guy I'm buying the rig from lives about 1600 miles away and isn't super at communication, so I still need to test drive and inspect, so the deal is far from complete. Ive given him a generous nonrefundable deposit to hold it for a while. Im taking the time to explore my options, search out different opportunities, perhaps find a shop I can work with if I go a different direction...

I appreciate your thoughts.



Imho he is asking wayyyyy to much. I wouldnt pay more than 10 and that is the top. The 4bt is a good motor. I would say you can get about 80 hp out of it


I'm in the middle of a p7100 pump 4bt conversion. Pm me with questions. There is nothing wrong with a rotary pump. They are good to at least 200hp. I'm on 4btswaps.com, you can find my thread there. I agree $15k is steep, unless it is immaculate.