In general, I won't pull a good running 304 or 345 for any reason. If it ain't broke, don't fix it, and there isn't enough of an improvement to be worth the hassle.
Well.. unless you have a BUILT 345 or 392 lying around.
But pull a good stock 304 for a stock 345? Nah.
I liked my hot-rod 304 for RPM. The valves floated at 6300rpm, but I would hold it there. Made good power, good RPM. I selected the 304 for the short stroke.
Then I built a not-lightened 392 (406) for my Travelette, and even though I didn't purposefully lighten the bottom end, and ran a lot less cam with less compression - I was tempted more than once to pull the 392 from the truck and put it into the race Scout.
..so instead, I'm building a tall-deck SV using the knowledge gained from the 304 project and the truck 392 to beat both - this time with more compression and more cam. A lot more cam.
It still isn't an LS1, but it should be fun.
As far as reliability - the 266/304/345/392 are all pretty much the same engine. There's very little difference between them. The 304 uses bigger pistons and valves than the 266. The 345 uses a longer stroke crank than the 304 and square intake ports, but uses the same valves. The 392 uses bigger pistons than the 345, and bigger valves, but the rods and crank and everything else interchange (you may have some balance issues to deal with!) with the 345.
So, on that front, the 392 should have less reliability - it has 88 cubes over the 304, but runs on the same main and rod bearings.
It all depends on how over-engineered you think those bearings are for the 304 in the first place.
07-14-2012, 10:35 PM
Re: whats your ideal ih motor?
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