What would a general rebuild consist of parts wise, and what usual processes are done while rebuilding?

 

Assuming that you re-use the existing crank and rods:

• vat all the parts to clean them up
• bore & hone the block
• turn the crank journals, to restore them to perfectly round and flat and smooth
• replace the pistons, rings, main and rod bearing, & cam bearings
• install new oil pump
• install all new oil passage plugs and freeze plugs

You can do all sorts of additional detail things; deck the block, drill oil passages, remove casting flash, tap all the holes, etc. etc. etc.; this is just the basics.

For the heads:

• disassemble and vat
• grind valves and seats
• replace springs, reatiners, keepers; and shim the springs to the correct height
• mill the deck surface flat

Again, that's just the basics, for a "stock rebuild". There are endless details beyond that. Plus, there are all sorts of things that one might do to the heads for performance purposes; port the intake & exhaust ports, use better valves, enlarge the spring pockets for better than stock valve springs, install screw-in studs and guide plates, shape and polish the combustion chambers, and on and on.

 

Does one do the bloack machining work first, or get the rebuild components first? Is there a danger of rebuild components not fitting?

Thanks,
Jason

 

Yes there is that danger.

Standard practice for a performance rebuild, as opposed to a crate-motor slap-it-together kind of production line job, is to bore and hone and deck the block to match the pistons and other moving parts, to come as close as possible to the desired tolerances.

 

My intentions were to drive my stock 305 while building a 350 block until I discovered oil leaks. How far with all of this stuff should I go before I should just skip it and work on the 350?

Thanks,
Jason

 

you'd need to know how much the block was bored or the crank ground to buy parts to match, so the machining would be done first.

 

That depends on the oil leaks.

If it's valve covers, just fix it. $10 and you're done. Not worth changing any long-term plans over that.

If it's a rear main seal..... that might be a different matter. That costs almost $20 by the time you're done with it.

 

Rear main seal definitely (it is oiling my clutch), and valve covers also. The engine seems to run smoothly, do the leaks really require rebuilding to fix?

Thanks,
Jason

 

No it does not require a rebuild; although it does require alot of work.

There's basically no way for a rear main seal to oil a clutch. About the only thing that can do that is the transmission. Are you sure it's not transmission grease (gear lube) on your clutch?

As far as rebuild procedures, what most performance machine shops will do, is to bore the block to within a few thousandths of the std oversize (like they might bore it .027" or some such), sonic check or magnaflux or pressure test it, then once they know it's good, bore it the rest of the way or just hone it to match the measured piston diameter.

Crank bearings it's best to wait until the crank is turned.

 

So my trans mechanic is taking out of his ***. As he replaced the trans and clutch my hope is to not have an issue anymore.

To change the rear main seal and the oil pan (which is bent, but not open) you have to take the engine out, right? What should I do here?

Thanks,
Jason