Re: 350 Sleeve or 305 block
 

My dart little m weighed 218. Almost 40 lbs more than unfilled stock block.

Re: 350 Sleeve or 305 block
 

Have used the same stock 305 block (filled) for 15 years. ARP main bolts, good crank and rods in excess of 7400 RPM, no issues in a stick shift stocker. You do need to pay attention to the stock block core shift though. Pick a good block to start. My 2 cents worth 🏁🏁

Re: 350 Sleeve or 305 block
 

If you want to go fast and have the best of the best the dart blocks are hands down the way to go. In the grand scheme of things they don't add much cost either if you think about all the costs associated with prepping a stock block. The 305 replacement is a nice piece, as are the little m and big m accepted blocks for those applications. Unless a customer already has a block and refuses to upgrade we don't do any engines without starting with the dart block, just make sure you get someone who knows what they're doing to hone it.