rocket280z

Whatever you do, don't put small chokes on your carbs. I know you said you wanted a lot of low end power. Power below 2500rpm is the same or less than stock once you put in a cam with more than 260 duration in one of these motors. So the only improvement you will see with the new motor is above 2500rpm. The cam you have, with apropriate head work, can make peak power around 6400rpm. Many folks put too small of a choke/venturi on DCOE carbs, 32mm, and limit that to less than 6000rpm. 32mm is an adaquate size for a totally stock l24, and ok for l28. Really the most you can make with the 32mm chokes on there is around 160whp, as they're literally choking the engine. You can make that with the stock 280z engine properly set up(ITS engine). You should put, at least, a 34mm choke in your side draft carbs. That should get your peak power above 6000rpm peak power(around 180whp) and only sacrifice 5-10 ft/lbs at the wheels below 4000rpm, compared to the 32mm choke. A 36mm choke would likely get peak power(190+whp) to the 6300rpm area, trading another 5ft/lb in the lower end. The length of your intake system is important, you appear to be on the right track with the timing, and naturally you need to have a decent exhaust system. Anyway, make sure you are using at least 34mm chokes, on that engine. I think you will find it's the best use of the engine he built you. Enjoy!