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I'm planning to rebuild my 68 240 I6 engine. The man I bought it from said he rebuilt it twice and has already bored it .40 over. I was wondering if it's safe to bore it .60 over. I was also wondering if putting a 300 head on the 240 would improve performance in any way.
I'm planning to rebuild my 68 240 I6 engine. The man I bought it from said he rebuilt it twice and has already bored it .40 over. I was wondering if it's safe to bore it .60 over. I was also wondering if putting a 300 head on the 240 would improve performance in any way.
Two rebuilds? How many miles are on the engine and does the guy have the documentation to back up his rebuild claims?
My '69 F100 240 has plenty of wear on it (best I can figure 175K miles if not more). I seriously doubt it's ever been rebuilt and it still keeps on keeping on. These engines would have to be very dilapidated to require a rebuild, let alone two. --not saying it isn't possible but, seems improbable.
Just the opposite with respect to a head swap. 240 head on a 300 is an upgrade.
Personally, if I was going to keep a six cylinder in my truck, I would swap to the stronger 300.
This choice is up to you but, if I was to buy an engine, I wouldn't be investing money on one that's at the brink of being completely used up.
Like John said, you can get an '87-'96 4.9L (fuel injected 300) engine (carburet it if you want to) and rock on. Part change for part change, you'll never get 300 power out of a 240.
I've got a carbeurated 300 but its slam full of water and would need rebuilding too and I've already got the 240 apart and I just figured it would be an easier process to rebuild it instead of repeating the same process all over on the 300. Im not looking for power, I just want it to run and be a daily driver.
Jeff, boring sixty over is not a good idea. You could end up with a water boiler or a cracked jacket from weakening the walls.
These blocks are plentiful and cheap. Why take a risk for $150 or so?
Jeff, boring sixty over is not a good idea. You could end up with a water boiler or a cracked jacket from weakening the walls.
These blocks are plentiful and cheap. Why take a risk for $150 or so?
2X. To make that motor dependable you would have to Sleeve the block. That's prolly more than the $150.00 investment of the engine.