Some Engine Rebuild Questions

[digger]

135mm M5x/S5x 24 rods (not all are the same length) are better than M20 rods if you find a refurbished set economically then do that or if spending on machine work better to do on a the slightly lighter set as no significant cost delta

i wouldn't spend extra on aftermarket rods there is almost zero real tangible benefit over the lighter OE rods used in some 24V M5x engines for a stock rebuild or pretty much any NA build except where clearance is an issue on a big stroke engine

once you start getting new aftermarket pistons you need to decide what engine you're building 2.5, 2.7, 2.8, 2.9L as then staying at 2.5L is pretty silly in most cases.
you need to be very careful with aftermarket forged pistons most designs are a waste of money, problematic and detriment in the long run compared to a OE cast piston which has 100x the engineering input and generally more forgiving from a honing perspective with the rings that come supplied

you dont need ARP rod bolts or main bolts and the parts need resizing if you do so potentially extra cost on top if that isn't otherwise required and for zero real gain for your use.

ARP head studs at least allow you to retorque them but with the stock gasket you don't really need to and the cost is very low for the OEM bolts so its hard to justify

[McGyver]

I don't have first hand experience with pistons and turbos, yet, but I know plenty of people boost stock bottom ends and get good life out of them. Digger makes a good point about picking your engine size - If you're going to spend the money on machine work and a rebuild, why stick with a stock 2.5 when you can go larger?

With the parts I had on hand, it made sense for me to build a 2.7. If I didn't already have a crank and rods, I would have gone for a 2.9. My engine will keep the 84mm bore, the first over pistons are NLA (84.25mm), so I went with second over (84.50mm, PN 11251714810). At the time, they were roughly $100/piston.

A torque plate is great if you have access to one, but plenty of people bore/hone without one. The cast block moves a lot, so even with a torque plate, the shape off the machine will be different than when sitting in the car. Then again, anything you do at a shop will be better than the original mass-production quality, and it's unlikely to matter for most builds.

I went with ARP for everything because I had my main caps and rod caps cut, bored, and honed.