S13-SR20 Auto-Manual Swap

[Brolewigi]

Now, this is my first time posting on this website. And I don't have all of the knowledge about Nissans.However, I have an extensive knowledge about Honda's. Specifically Integras. I am planning on getting rid of my Integra and getting a 240sx. I found a beautiful 90' S13 AUTO for the perfect donor car for an SR20. The car is in perfect shape, the body has minor problem (Considering it is from a Junk Yard) but the interior is PERFECT!!

Now to the question at hand. I have read and helped put in an SR20 into the 240 chasis. However, I want to do a automatic to manual swap because the car I am buying is $600. I was wondering what pitfalls I could possibly run into while doing this? Also, One of my friends owns a shop and has done quite a few SR20 swaps. He is trying to get this one car started in which he did a auto to manual swap. I searched for this topic and I didn't find anything that suited my needs. Thanks for the help!