Your local library usually has the engine rebuilding books, even
specific to that marine engine.

Cheap manuals like Haynes have all the specs and clearances and torque
settings at least.  They are pretty good for a beginner.  The Chiltons
assumes you know a bunch.

For the bottom end, you need to plasti-gauge it to see if it needs
touching first.  Basically you can buy the gauge at auto supply shops.
It is a plastic rod that you stick between the bearing and the
crankshaft.  You remove a main and a rod bearing cap and stick the rod
in, then you tighten the bearing cap back on with a torque wrench.  Then
open it and see how flat the gauge got.  They come with a chart so, so
flat means it has so much clearance.  If that clearance is within specs
and the bearings look nice, you leave them alone.

Otherwise you need the book to see where the over and under sizes are
stamped on the engine.  Usually around the oil filter.  You then need to
look for marks on the crank and on the back of the bearing shells to see
what size they are.  Bearings can be over and under sized and if the
engine was played with already, that crank is likely already at it's
limit.  Then things start getting expensive.

If everything looks pretty and the gap is a bit big according to the
plasti gauge, you can sometimes get away with just putting new bearing
shells in at the same size that came out or .0001 or 2 or something like
that oversized if the plastigauge allows.

Good luck!

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

oil starvation would wipe the lifters.
The question is what?  I think the BBC uses splash oiling from the heads
to oil the lobes like a SBC does.  If so, do you have plugged drainback
holes in the heads?

You need the cam and lifters.  The lifters don't have to be comp, but
they need to be new.  You really should put in new springs to go with
the new cam - same thing - they don't need to be comp, but you need to
match the specs (pressure) or you might get valve float - my buddy's
Nova felt like it picked up 50hp at 5000 rpm with new springs vs the
stock springs - they were too weak for the new cam - his stock cam and
stock springs were only designed for 4000... you also run the risk of
coil bind if the new cam is bigger than the old one.  IOW, get the
springs.

FWIW, the price of the kit is usually cheaper than buying it all
separately.  The only thing you don't really need is the timing chain,
but you should probably put a new chain in anyway, so I'd probably do it.

I just did bearings on a SBC 307 for my dirt car, and I have one piece
of advice - get a ridge reamer and a ring compressor and pull the
pistons.  It's a real PITA reinstalling the crank with the rods in the
way.  And if you've gone that far, a set of rings is cheap insurance you
won't have to do it again...

And you cannot be too clean.  Consider spending the $30 or whatever it
costs to get the block hot tanked.  It's much nicer than scraping off
layer after layer of pennzoil frosting.  The stuff on my 307 took
multiple attempts to get through with a pressure washer.  It needs to be
spotless inside (especially inside) and out - you don't want crud in
your new bearings, do you?

I'd also recommend taking your oil pump and replacing it with a high
volume one with a welded on pickup.

And yes, at this point you've pretty much rebuilt the whole thing.
It can be done, but take it slow, clean everything, and measure
everything.  Or pay a pro and farm it out.  20+ hours to disassemble,
clean, measure and reassemble is probably a low #...

Ray

It is always a good idea to have them checked for guide
wear, reseat them and install new seals.

You will have to look at the specs on you stock springs,
etc.  IIRC, the stock springs in the BBC are a bit on the
iffy side in a hard working stocker.  If the new cam has
more lift or the duration makes for more aggressive
acceleration ramps, then valve float and damage can be a
real problem.  My experiance with CompCams is that they will
not steer you wrong with a particular cam.  It may be that
they have a less aggressive cam that will allow you to use
more of the stock components.  My experience with boats is
that if 300HP is good enough for a ski boat, then 400HP will
be better and 500HP is very satisfying - until you can
afford more.  That is where their recommendations come in -
to keep you from going past the point of reliability with
good performance.  If the BBC marine setup is like some of
the automotive engines I've replaced cams in, you are in for
one pleasant surprise when you push the throttle up the
first time even with a mild cam upgrade.

That would be wise if you go forth with the cam setup.  You
are going to need an engine stand so you can roll 'er over.
You are going to need a good torque wrench and a shop manual
for the BBC.  It's not a real toughie since you are going to
have the front end off if you install a new cam.  One of the
most important things to do while you are working in this
engine with the cam out is to check and maybe replace the
cam bearings since you have the cam & lifter problem.  That
is a job for an automotive machine shop.  It may be that
your engine actually needs very little other than a new cam,
lifters and push rods.  A new set of rod and main bearings
is no big deal since you have it down.  Just make sure there
is no evidence of crank journal grooving or oil starvation.
If that has happened, you are in for a total rebuild.  A new
oil pump would also be a prudent and inexpensive insurance
replacement right now just in case the problem was a sticky
pressure plunger.  Be sure you get the oil pump properly
oriented when you install it so the distributor is where it
should be.   We used to drop the pan on our short track
Chevies every 2 weeks just to replace the bearings if
nothing else.  At 9K RPM, they needed to be good.

Lugnut

I don't want to sound like a wise guy here, but do you really want the first
engine you have rebuilt to be the one in your boat, thats quite a chance to
take.