Have any of you guys bored your 6 liters to a 427 (more or less). I have been thinking about it. I wouldl like to know the ends and outs.

 

I wanted to till I heard it was about $6000 to re-sleeve the block. Then you still have to buy the stroker crank, and new pistons. But it would be badass

 

From my rough guaging the 4.8/5.3 blocks and the 6.0 blocks' cyl wall thickness is basically the same. It would be the same difference as boring a 4.8/5.3 to a LS1 bore 3.78 - 3.900. If you went with 4.125 bore and 4.100 stroke you'd have a 438. That is what I am planning on doing. That is why I'm saving my 6.0 block for my 81 Vette and doing a 346 in my truck. I don't know of anyone that has actually done it but I wouldn't hesitate to do it to my own block. The thinest I have found the cyl walls to be is .260". That would still leave ~ .200" thick wall after boring. That is over twice as thick as I have personally run before on high Hp 400 small blocks, gen 1 of course.

 

Redaddiction had a 423 and was selliing it for $6000 in Oct. He is off at boot camp right now. I don't know if he ever sold it or not. He should be back in a few weeks maybe he will see this and chime in.

 

427 is doable with a 6.0 block if you go with a 4.125" stroker kit.

 

The is one important issue with the large cube iron blocks. The problem with putting long stroke cranks in the 6.0l iron blocks is that too much piston comes out the bottom of the cylinder bores at the bottom of the stroke. Yes they will make great torque, but the wear we've seen on the piston skirts after a short running time is high. Also, the pistons rock excessively at stroke bottom and that causes the rings to wear more rapidly. Suffice to say I don't think too many of these engines are going see 100,000 miles without refreshing once or twice...........

Richard

 

I imagine a fairly thin sleeve that is longer would solve the problem. I have seen that done with gen1 engines but haven't looked to see if that is possible in a gen3. Most shops in my area charge between $60-100 per hole to sleeve. I think the $6k may be for the special large bore sleves for LS1 aluminum block???

 

yeah 6k seems high to resleeve since i think you can get the c5r block or what ever its called for that price or less.

 

It is possible to add a longer sleeve, but the added cost makes the iron block less desirable. Normally sleeves pressed into iron blocks seat at the bottom of the block's bore, but since the new sleeves would need to be extended, it would require a step be placed somewhere else. Maybe at the top of the bore.
The C5R blocks have the extended sleeves and usually require some notching to clear long stroke setups. None the less, it does add stability to the pistons at the bottom of the stroke and we see much less scuffing on the skirt and ring wear.

Richard

 

If you are not in a hurry wait for the LS7 block to come out... shouldn't be too long and should be cheaper than a dry sleeved LS2. Cheaper than a sleeved LQ4/9? Don't know. LS7 = 4.125 bore out of the box... 4" stroke and there you are. Another block that will be out later than sooner will be the L92 aluminum block with its factory 4.065 bore. And since you are building a motor for a truck then you will also be able to utilize the L92 heads and truck intake. The new L92, I think, is going to be an awesome alternative for guys scratch building a motor.