Thank you for the reply, yes its odd drive train wise, but https://www.gmheritagecenter.com/doc...olet-G-Van.pdf lists it on page 3 4l60e in g30 under 8600lbs gvw. It's a very clean, low miles van so that's why I purchased it, even with its substandard drivetrain. The reason for considering the 165cc Dart head is I have used them before for towing on another vehicle and they flow very well. Intake Port Flow: 232 cfm @ .500” Lift / 28” Exhaust Port Flow: 138 cfm @ .500” Lift/ 28” is from the sales propaganda. They actually do these numbers and a little more when touched up with cartridge rolls. I will not need any more head than this for what I am doing. Some confuse the darts with world products offerings. World's small heads are very rough and have poor stock type chambers.The block is a roller compatible, borescopes through the distributor hole are great. At least all the parts in the valley are fully machined for a roller, so I am hoping the part behind the timing chain is done too. I have the ramjet cam, so that's probably what it will get, but I appreciate the advise. Right now I am more concerned with learning the programming part, the mechanical stuff can change.