Big Block Chevy Build

[Mike Peters]

Between you and Chris, no I can't!

Yeah, I can't believe Chris is so hard on you.

[wikd69]

Bruce,

I ended up at 9.75 with this little blower motor. If I had originally went with a bigger crank (instead of this 427 setup) I would likely be a lot deeper into the 9's than I am today. Of course, my motor build is nostalgia pro-street and the 427 choice fits perfectly for me. If you go with a bigger displacement, invest in quality stuff (4340, etc.) you can push that orange beast as deep into the 9's as you want, with minimal upgrades required along the way. Like everybody says, invest in hardcore foundation and then incrementally build from there. I think the term is, as you put it, start at 'Nasty Bitch' and go up

[Bruce69Camaro]

How about two bolt vs four bolt?

Do I need a four bolt block, which I think would be better, but can a two bolt block get the job done?

If I go to a junk yard, what donor vehicle should I look for and is there any problem using a tall block?

[John_Heard]

4 bolt would be certainly best, but if you must a 2 bolt will take a lot more than most think. Problem is with them at higher horsepower levels you will get cap walk and fretting issues.

A tall deck would be nice as well as you can get a better ring package in it, but once again, it's not totally necessary. I like the old tall deck truck blocks myself, I've got two of them. 4 bolt mains, 10.2 deck quite beefy for OEM.

[Bruce69Camaro]

Any idea on what Chevy truck years to I look for?

I got a friend that hauls cars from wrecks and also to the scrap yards and I'm going to have him keep an eye out for me for a motor.

[John_Heard]

Don't really remember, I'm thinking it was like big grain trucks, dump trucks, stuff like that. I have one that is stamped MARINE on it? Frankly those old tall decks aren't going to be easy to find now I bet, you'd have a lot easier time finding a aftermarket block. OEM Short Deck shouldn't be too hard though.

[Bruce69Camaro]

WOW that was easy, I just got a message that a very good friend of mine has a 454 block already machined and ready to go and payments can be made!!!!!

If I know him, it was being machined to be made into a 496.

Step 1- Almost complete......

[John_Heard]

I don't think you want a Gen 5, seems like there was an issue with coolant holes on those. I don't think heads interchange with those.

[supernova]

I have a mark IV and 2 gen 5 tall deck blocks. The gen 5 block will work with any head as long as you us the right head gaskets and there is a difference. I built a 525 blown street motor with a gen 5 for a guy last year. Head gaskets and rear main seal adapter for a two peace seal were the only concerns. Worked great and it scared the crap out of the guy the first he stepped on it. I think it's a car show now.

Having used both types of blocks IMO the mark IV block is better. In Bruce's case I would stay with a short deck block.

[Bruce69Camaro]

The block that is being offered to me is a mark IV block w/ arp studded two bolt mains.

[John_Heard]

I couldn't remember what the deal was - that's good to know they can be adapted and still used.

I'm going to build me a tall deck 496 flat top engine one of these days for my old 72 Chevy Pickup. Been slowly getting parts for it here and there. Should make for a fun street truck - I think the 3 on the tree will have to go though lol

[Bruce69Camaro]

3 on the tree......that's awesome, I say let it in

Boy that brings back memories of getting the shifter linkage all jambed when beating the company work truck.

Sad thing was, I used to get scared that the boss would find out, hell he got it jambed worse then I did!

[John_Heard]

Yeah I used to carry a big ass screwdriver to unjam those things back when I was young and thought it was cool to try and speed shift one

I think I'll change it over to a TH400.

[wikd69]

The block that is being offered to me is a mark IV block w/ arp studded two bolt mains.

Bruce - I would explore getting that block converted over to a 4-bolt setup. As with everything else, your mileage will vary. If you research it on the web, folks will state they ran huge horsepower and low-ET's with ARP studded 2-bolt blocks, others recommend doing the 4-bolt conversion (or going with an original 4-bolt block from the start). One thing also to consider is how much the fellow wants for his studded block, and what you'll throw away by not using the current studded setup. Main stud kits aren't all that spendy, but it is green money.

If you look at converting, you'll need to obtain new caps, get the machine shop involved to drill and locate them, get the block line-bored and then you're good to go.

This all comes back down to the foundation thing, right ? What shortcuts do you want to take at this point, and how much horsepower / stress do you want to allow for down the road. How much horsepower and torque, how high do you plan to wind it, etc. IMO, if you go the distance now and invest in a 4-bolt setup you'll forever have that out of the way as a concern.

Of course, I tend to over-build stuff - down-side to that is increased cost and build times - up-side to that is it doesn't break down the road

My little 427 street motor is a 4-bolt conversion from a 2-bolt 454 block and I've spun it up close to 8,000 rpm quite a few times without issue. Of course, now that I've said that, we'll be sweeping rubble off the track after my next pass.

Decisions, decisions...

[John_Heard]

Again, it boils down to how fast do you want to go, and how much do you want to spend?

I do know for a fact that you can go deep into the 8's with a 496, double cross plate, flat top pistons, low buck short deck two bolt main motor and it's likely it'll live for at least several years if all goes well. Adam Wright's car is a perfect example, and it weighs 600 lbs more.

No doubt an aftermarket block, 4 bolt mains, etc. etc. etc. will increase lifespan, and maybe make a little more power, but it can be done on a budget if that's what you need to do. Just remember there is no replacement for displacement