I just commited to a used 454, marine application, std bore short block for $100. I figured at $100 i could take the chance that the block and crank are ok. I have only had smallblocks in the past so i know very little about BB. I want to make this as much of a budget build as i can, so I know i will be making some visits to the junkyard for parts such as brackets, pullys etc. My first question is what vehicle would i look for in the junkyard that would have a BB with the accessories i need? Also is it OK to leave my SB coil springs in with a BB? One more question, What am i looking for in a set of performance heads? square port vs oval port, valve size? Thanks

Oval port heads only, 2.19"/1.88 (2.19/1.78) will do nicely. Front accessories of any BB pick-up will work (take everything P/S pump brackets, exhaust manifolds, water pump, alternator, and brackets, A/c if using one, and air pump and brackets). Springs, chassis motor mounts, cross member, radiator have to change. I would also upgrade brakes because your performance just took a major jump in acceleration; it would be nice to be able to decelerate just as quickly.


Larger Dave

Be sure you check the block for excessive corrosion of the coolant passages and deck surface.
If it was a closed cooling system it should be fine, just look for freeze cracks too.

Marine 454's were usually 4 bolt main.

Unless you have ALOT of local wrecking yards that have BBC powered vehicles, forget scavenging for the brackets and pulleys. Buy the pulley on Ebay in aluminum or stock used, and buy the brackets new from GM. ALL the brackets for the Alt and PS are about $45 new from the dealer. When you take into account the time and gas to call around, drive around, pull the parts, clean the parts, etc, $45 is a bargain.

If you need the GM PN's email me at jakeshoe@hotmail.com with BBC brackets in the subject line and I will give you the pn's.

They're not only four bolt blocks, but they are all tall deck blocks if they are a true "M.TRUCK" which denotes the marine block, from the passenger equivalent often used by Mercruiser in big I/O's.


Larger Dave

Be sure you check the block for excessive corrosion of the coolant passages and deck surface.
If it was a closed cooling system it should be fine, just look for freeze cracks too..
Add to this, if closed cooling system, you should be fine. If open cooling system, salt water and iron don't mix, they are natural enemies.

I had friend with a boat. Fourth year on engine, cranking up for spring, no turn over. Pulled the head, cylinders full of rust. I could, and did, poke a hole through the cylinder wall with a screwdriver. New engine went in next month.

That being said a 454 forged steel crank and HD rods are still worth the $100. (the front timing chain cover, cast iron Q-jet manifold with extra coolant bypass hoses, and the cool truck only water pump with extra bypass hoses, and the oil pump drive shaft are bonuses).

If it is a M.TRUCK block it should also have a seven to nine quart deep truck oil pan that will not fit a passenger car (especially in today's low riders). Since I replace pistons and oil pump when I rebuild an engine, I am not counting those. Besides a Tall Deck truck/Marine engine has four piston rings instead of only three as found on passenger cars, a longer than stock length water pump to fit on the air brake air compressor to the front of the block, and a stump puller cam that is all done by 4800RPM. All of these parts make great conversation pieces when left upon a work bench for visitors to gawk at.


Larger Dave

How do i tell if it is a tall deck? Is there something obvious? something i can measure?

Tall deck will be about 3/4" from top water pump hole to the deck, standard is more like 1/4". Also, lots of tall decks run two thermostats, housing will be obvious when you see it. Good luck!

Here's a link to a page that shows using a late model F body serpentine setup on a big block. Seems to be in line with your "junkyard build" if you want something a little more modern.

http://www.camaros.net/forums/showthread.php?t=39678&highlight=serpentine

For those who mentioned the cooling system, you were correct. It looks as though it was an open system due to corrosion. Also it IS a standard deck (measured at 9.8 from crank to deck), and it is a 4 bolt main. I'm gonna buy it and hope the corrosion can be cleaned up. If not at least i'll have a crank and rods out of the deal. Ill let ya'll know how it turns out.