Hi! This is my first post on hybridz.
I'm 21 and have some experience as a home mechanic and have been tinkering with my 240z that I've had since high school. The car is a 72' 240z with amazingly little rust. However, the car has never ran reliably and had a rebuilt 'mystery' engine with e31 block and e88 head which I don't believe would be correct for the model year. Long story short, Eiji at Datsun Spirit is building me a 3.0 liter l28 that should make around 300hp at the crank. I've decided the best route would be the KA 5 speed swap and an sti r180 diff as this should be adequate for my power level and driving style and require the least amount of modification. I'd like to keep this car street-able as it is my cruiser and I don't plan on racing. I'd like some help from some more knowledgeable people on recommendations for the sti r180 diff. I know that there are 3.9's available although the 3.54 is much more readily available on eBay. I liked the feel of the stock 4 speed drive ratio so I wanted some recommendations on which ratio would pair best with the ka 5 speed
ps. I included some pics of the car and DatsunSpirit engine for anyone interested