StingrayDK

Hi all,

Ive been trying to find out if I had a 2 or 4 bolt block in my car, well somedays ago I pulled the oilpan to make sure! The result= 2 Bolt

I know that an 2 bolt block is supposed to be plenty strong in it self but I guess there is a reason they made the 4 bolt? My block number is 3970010 and from what I understand its a good block with 1% added tin in the casting. My question is, if I send the block of to the machine shop to get it prepped for a stroker crank would it be stupid not to get splayed main caps installed at the same time? Or is it a waste of money?

Thanks


[Modified by sting74, 12:33 AM 3/11/2004]

PatsLs1vette

it all depends on what your looking to get out of it,horsepower wise,if your looking to go all out ,then maybe itll be your added insurance.Ive built plenty of 2 bolt blocks that have withstanded way more then your average street abuse and never had a main failure.Look at your future at what you plan on doing with it down the road also.Also look at the price of labor and the splayed caps and decide also.How many rpm's are you going to be turning?If you do ,do 2 bolt at least install arp main stud kit.


[Modified by patsnitrovette, 7:54 PM 3/10/2004]


[Modified by patsnitrovette, 7:56 PM 3/10/2004]

ZD75blue

I went with some ARP bolts for the mains...

The research I did stated that installing studs preloads the block... and puts it out of square... so ya have to get the whole deal align honed or in some cases hogged out!

For me... it wasnt in the cards this time around... but I still went with ARP's stuff for the little bit of insurance over re-used strecthed hardware :cheers:

442olds

You can use a 2 bolt block for a lot more than people give them credit for. Unfortunately everyone thinks 4 is better than to in just about any application. I just buttoned up my 383 LT-1 with two bolt mains. For my pocket book it made more sense to just stud the bottom end than to convert to 4 bolt splayed. Align honing is about $100 and if the guy knows what he's doing won't remove a significant amount of material in realtion to the crank height. Studs are cheap and load the block better than bolts do.

As an example of what a two bolt block can do, my nieghbor had a 468 big block in his 9.5 sec 72 monte carlo with a studed two blot block. He ran pass after pass without failure and made about 850hp on alky w/15:1 compresion. And he was even considering a 500 shot of nitrous or a large 12-71 blower. But I guess we'll never know if it will have held up as he killed himself in a drunk motorcycle accident. Don't feel bad, he was a butt!

comp

a balance job, makes a Big difference :thumbs:

Ironcross

You may get a way with a 2 bolt, but you obviously want more HP, higher RPM`s and more compression or else you wouldn`t want a stroker kit. The main caps have a tendancy to walk or chatter with out the benifit of the added strength 4 bolts will give you. The engine will live a lot longer stroked, with a 4 bolt set up. It`s wise insurance. Cranks are not cheap, do it right. :thumbs:

PureSilver

A guy named Vizard has a book out on budget building the SBC (Small Block Chevy). He claims the two bolts are good for 450 hp or more, and the standard 4 bolt mains really don't go into the block but stay in the same web. If you do decide to go, use the splay bolts as they get more strength from being in the block side. Line bore is necessary afterward.

I'm running a 350/350 with two bolt mains, and don't expect any problems.

Your extra tin helped the metal flow in and form to the molds better- it's good to have.