This list says 75-87 454 4 bolt mains.
http://www.chevellebigblock.com/pdf/...ockCasting.pdf

But this one says 78-87 454 2 or 4 bolt mains.
http://www.roadsters.com/bbc/#blocks

Nothing wrong with building something with your sons,
so long as you know the real cost and you have the funds to finish it.
No matter how you slice it you will be looking at $5000 going up from there depending on what HP you are looking for...
May be more fun to do a simple upgrade to what you have since its already rebuilt,throw some heads+cam at it, gain 50-100hp and go out and have fun on the boat with your sons and use the extra money for gas!

I did the honest leg work with getting a shortblock to me and the shipping, duty, taxes, to my door or a reasonable pick up place, is huge, so starting from scratch is the way to go for me. If someone sells me a short or long B for say 3 k its goes up to at least 5 k by the time its to my door.
I understand the advice about the cost but its gunna be 5 to 7 grand no matter which way I go so I may as well start from scratch. The only thing that is frustrating the hell out of me is I can't find a 502 block anywhere. I would so much rather start with that platform.
The engine I currently have I will use while I get the other ready. I think I will keep it as a spare or stick it in a truck to sell.
If I can get an engine to my door for 3k I would consider what the goods are but thats not gunna happen. Block, machining, forged internals, takes me to 3k here so thats the math. Don't get me wrong I am thankfull for all trying to save me money and problems, but getting an engine into Canada is expensive.

Your lucky to have 2 sons to enjoy an engine building project with. When I was growing up I was always working on something. Lawn mowers, go carts, mini bikes, motorcycles, cars, trucks and finally boats. My son never did show any interest in this and would rather sit in the house and play video games. You can't make them do something they just don't care about doing. My 16 year old daughter comes out and works with me wanting to learn more than my son ever did. Enjoy it while you can.

All 502 blocks are siamese bore 4 bolt mains. All "factory assembled" 502's are forged crank, good rods, forged pistons, GM rect port heads.

I agree that you would be better off to start with a 502 block, but if you can't find one, you can't find one.

Mk IV motors will require tie-bar roller lifters if you run a roller cam (hyd or solid). Tie-bars are good lifters, but they add mass, and are expensive. Most Gen5 and all Gen6 motors will have factory dogbone roller lifters which are fine up to .550 lift.

Valvetrain is stable when lift is kept moderate and rpm is kept below 5500. Factory valvesprings are a weak link on BBC's. Stay below .550 lift and run good springs for "hands off longevity".

Good luck.

Ya pickle its always a struggle at our home with the kids screen time. I am of the belief that we as parents have to offer an alternative for them and at our home if they don't like my activity then there is always chores to do.

Mcollinstn

That is some great information you laid out for me. Thats the kind of stuff I need the heads up on. I don't fully understand all of it but do get the point that the gen 5 and 6 are set up for a roller application where the gen 4 require aftermarket stuff to make full roller. I hope I understand that correctly. As far as the other info I will cross that bridge when I get there.

Any idea what generation this last suberban engine I have a chance at is ?

What is a "siamese bore"

Where the heck do you live? It costs $450 all in to ship a 502 long block from Massachusetts to my door in Vancouver BC..

I live in Winnipeg.

I would like to here how you did that because I was quoted 2 k to get it done. I called Canada customs and I would pay taxes on a short block or long as if it were being bought new from gm so the tax alone was over 400 bucks.

Who was the shipping company?
what was the tax and duty amount?
where did they deliver it to your home or buisness?
did you have a loading dock? or was it to your home?
I want to here all about how you did this please.

I dont care how I get this block! the cheaper the better and if I can get a 502 that would be sweet. I can always take it apart with kids and click everything back together.

Your right no blowers. call CSU get a carb, call me get turbos, convert your manifolds to accept turbos, make 700 HP, go fast.

Done.LOL

My buddy has a 502 long block for sale right now speak of the devil. Located here in CT Probably needs a re ring and bearing been sitting in storage for a while but was a low low hr engine PM me if interested and I will get you in touch with him.

Id still go turbos if it were me but I am a turbo Junkie