Theres a few different ways to skin the cat on these builds. First you need to know what you want out of it, what you have in existing parts, and how much you can spend. I've built 340 and 360 based and there's a few things I consider "must dos" beyond what I might do for a factory discpalcement build.
1. Sonic test the block. Mopar suffer greatly from core shift in the bore castings and the side loading of the longer stroke can cause wall flex or cracks in worst case situations.
2. Use studs in the main caps. The Mopar caps ae strong as is, but the bolts can allow cap walk and the center of the caps to flex under heavy loads. Especially using the weaker cranks the best solid foundataion without excessive spending is what you want. For $60 you can get a real improvement.
3. Internal balance the assembly. External balancing adds stress to the crank and block's main structure. You will have a smoother running, more powerful, and longer lived engine if you spend the extra couple hundred to internally balance.
Otherwise there's a few unique things too. Remember the crank is 11 (360s) or 18%(340s) longer stroke, and the stroke makes the most difference in any build. You go longer stroke, the rpms at which any power will be made it reduced. So the parts you look at in the books will give rpm ranges for power production. They ae not based on a stroked engine, and you want to go about 20-25% larger for things like camshafts and cylinder heads if you want to keep a nice well rounded engine. For heads I dont think using a head of less than 240cfm @ .500 is worth it. Some guys do, so this is more of a taste thing but I want enough port to feed ti fromm idle to 6K...lol. It's very easy to build a torque monster that can't make power past 4500 by simply following catalog info. The connecting rods... Factory rods with nuts and bolts will need the bottoms of the bores clearanced. Rods that use cap screws (LeMans type design doesnt use nuts...) should clear with no mods. Pistons.. Use forged. Period. No cast or hypers. Cranks - Eagle cranks are the cheapest and should be limited to builds under 450hp if you build like I do, 400 if you dont. They are cheap for a reason. Scat cast (which is also the MP cast) are much better and I have several making beyond 550hp with them reliably. Carbs - there are dry flowed and wet flowed carb ratings. Wet flowed is the better test mode because it takes into account the fuel in the airflow rating and will usually be about 18% more flow for an advertised size. Examples of dry flowed are Holley 4150,3310, 4160, etc and all Edelbrock carbs. Wet flowed are Holley Street Avengers, Race series, Demons, and most custom shop carbs. If you run a dry flow rated 750 cfm (around 680cfm wet flowed) you will leave power and economy on the table. I start at 870cfm wet flowed for my mild 4" engines.
