I build my own engines for FAR less than what the workshops cost. For long distance (longest single trip I've done is 15,000 miles while towing), I go all the way for a little more get up and toughness. Whatever you do, don't drill the original Model A crank shaft for oiling the mains. You'll almost certainly have it break on you. Here's what I do
- New counter balanced crank
- New rods
- Inserts all round
- Pressure feed the middle main bearing only
- Full flow oil filter.
- Air filter
- Down draught carb (Ex Holden Grey Motor Stromberg but weber is OK)
- Opened up inlet manifold
- 5.5:1 head
- Improved cam (about the same timing as an IB 330 but only 0.290" lift).
- Lightened flywheel
- Very importantly, properly balanced
Those motors are backed up by a Mitchell O/D so when I'm travelling at 50mph, the motor is turning at the rate a standard transmission would have it at 40mph. It does that all day, every day for many thousands of miles