Rebuild Time? Options

[Fyrmdk914]

Okay guys, I learned my lesson with my previous post. I am seeking knowledge from the panel. I have a 75 1.8, with 79k on the speedo. I assume that is at least 179k, or maybe the speedo has been changed, and the 79 doesn't have anything to do with the mileage on the engine. As far as I know, and the PO, this engine has never been rebuilt. It is currently running dual Delortos, I don't know what size or model. I use this car for commuting about 100 miles one way, once per week. On my last trip to work, she started blowing blue smoke when under compression braking, (going downhill). It doesn't smoke when under a load, or acceleration. The temp guage stays in the normal range, and under acceleration I don't notice any recent lack of power. There are some oil leaks with the engine, and not knowing how many miles are on the engine, I feel that it is time for rebuild. I do not have the tools, facility, or knowledge to rebuild myself, so I though about buying a long block. I have a friend, (not real local), that can help me with the swap out, but I do not want to impose on him to store the vehicle waiting for a rebuild of the original. I would like to stay at or under 2.0 liter, (for economy), and would like to run the dual carbs. I did look at the Raby Big 4, and initially I feel that I don't want to spend that much. Feedback and guidance? (IMG:style_emoticons/default/wacko.gif)