Yes, but it ain't something the average Joe could do in his garage ...
http://shop.store.yahoo.com/hm-performance/839025.html

 

It should be done by a machine shop, new holes are drilled/tapped, then the block is line bored with the new caps in place to insure its true.

 

2 bolt blocks can make a lot of power, how much are you planning on and what ci?

 

Originally posted by SouthFloridaVelle:
Is there any way to convert a 2 bolt block to 4 bolt? I heard someone that said they did it. Could you just drill and tap a set of holes for the outer bolts?

Thanks,
Todd

Todd

We install alot of splayed caps on both 2 bolt and 4 bolt blocks we use a 7.500 wide flat bottom cap with a 10 degree angle on the outer bolt holes as many caps out there are up to 22 degree angles which in most casse will get you in to the water jackets. We do all our work in a CNC machine, It cuts the register 7.500 for a flat bottom cap and it drills and taps for the outter bolt holes in just under 20 minutes and from there we line bore and line hone in most cases we install a front billet cap and strap the rear main for the high horse power applications.

I will try to send you some pics of a block we have done this too to give you a better idea.

 

Well me and my brother found a True LS6 for a steal ($4000

) It was sitting in some shop that they were clearing out. The owner passed away and the shop owner did not even know what he had on his hands. The P-O-P was sitting in the glove box. And we found a build sheet.

Needless to say, it did not have the engine or trans. We are planning on restoring it to as original as possible. But neither of us can afford a true 70 4 bolt 454 engine, nor can we find one.

So what I thought we could do is get an LS5 block, get it 4-bolted, and build it up from there.

Is there any difference between the LS5 and LS6 block besides 4-bolt/2-bolt?

-Todd

 

Todd,
I'm only giving you this information because you mentioned that your finances are limited.
The TRUCK big blocks (366-427) all have 4 bolt caps that are a direct fit for 396-402-427-454 Mark IV blocks. At one time, the 366 truck blocks were fairly easy to find (out of dump trucks, school busses, Coke/beer delivery trucks, etc, etc). If you are not in a real rush, look around all over to see if you can locate a junk 366 truck block (or even a 427 truck block). Get the 4bolt caps off of the block, then sell the bare block to a ship company for an anchor!
You will need to locate a VERY COMPETANT machine shop that can fit the caps and line bore/hone it to finish. It has been about 6yrs since I did the last conversion like this. The caps cost me $10. REGARDLESS of what 4bolt caps you use, you will still have the expense of line boring/honing.
This is a VERY good way to convert a 2bolt BB to 4bolt, as long as you can locate a junk 366 donor block. This is the poor boy's way of doing a 4bolt conversion----------------------not necessarily the best. But then, they were quite durable for Chev. With a BB, the registers (that's the gap in the main webs where the caps fit) were the same dimension for both 2 and 4bolt blocks. But, for SB's, the registers are totally different between 2 and 4bolt blocks. Thus, it isn't as easy (or as cheap) to convert a 2bolt SB as it is to convert a BB.

 

Originally posted by SouthFloridaVelle:
But neither of us can afford a true 70 4 bolt 454 engine, nor can we find one.

Hate to say this, but in my opinion a LS6 is not the kind of car which you do halfway. Either do it right, store it until you can, or sell it. Sorry.

 

Any reason not to just do the center 3 on a big block, just like a factory small block or splayed small block conversion? That leaves the factory position of the front and rear main caps just was they were when the block was first fitted for caps. According to the folks that I know that do alogn boring, having either or both of those caps really helps in getting a perfect align bore. I've also looked at doing a few conversions and anyone looking to do this should gather as many sets of caps as they can find. I've found some to be so close that you would have sworn that they were factory machined for that block and others that were so far out that no align bore or hone would ever get them to match up. HTH

 

Originally posted by 67 GTO:
Hate to say this, but in my opinion a LS6 is not the kind of car which you do halfway. Either do it right, store it until you can, or sell it. Sorry.

Yes I relize that. We already have a ton of NOS parts here or on their way. This will be restored correctly. But until we can afford/find a true LS6 block, I was thinking this would be a moderate solution... Until we find that block/engine.

I really would like to do this right, but I do not want this car sitting for another year or two until I can find the engine.

-Todd

 

Todd,
I totally, 100% agree with that approach.
Also, REGARDLESS of what engine you put in the car, there was only ONE correct engine----------------------and its gone. So, proceed as you have mentioned. Even if you should ever find a true LS6 454 block, with an acceptable date code, it still won't have your car's VIN stamped on it.

 

Just curious but if you don't have the correct block why the 4 bolt caps??
Save your money & use the 2 bolt until you can find the block you want.
Unless you are planning on over 700HP or spinning it to moon,, a two bolt block is just fine with studs & a line hone in a rat & once the pan is on I doubt anyone will be able to tell the difference

 

Well I could always have a block decked and restamped. ( Jokingly......) I would honestly never do that.

Other note, that is a good point....... Why spend the money?

Thanks for the input!

-Todd

 

I was wondering what dzauto said about fitting used 4 bolt caps on from a 366. I have a 4-bolt 454 block that lost its caps and the machinist in town told me to call the chevy dealer and see about ordering semifinished main caps. they quoted me $167 for all five 4 bolt caps the most expensive one being the no. 5 he said thats the easiest way to correctly get caps on the register and line bore it for best results. Jim PS Im willing to sell or trade the block cheap. it's out of a 80 pu and bored 60 over.

 

Todd,
I agree absolutely, 100% with Mike (Wolfplace). That would certainly be very sensible. But, I responded as I did because you asked the question.

Jim,
The 3 BBs that I have converted to 4bolt mains were all done using 366 caps. There is an engine salvage business here in OKC and they used to have tons of 366 caps----------------for $10/set. The machine shop that I use is capable of doing anything. Each time I had an engine converted, the results were dead on perfect!

 

Hi dzauto, I called the machinist today and he wants 325 to line bore the new mains to the old block, is that about the right price? i figured that and 160 for the caps and it's way more than I want to sink in this block. It's good to know that it can be salvaged if someone needed the block though. Jim

 

DZ, sorry if you took me as sounding harsh, but I was not trying to be at all! I totally agree with you both..

-Todd

 

There are a few sets of big block caps on ebaymotors.com (both 4 bolt). Go to ebaymotors.com and in search, type in "402 block"

-todd

 

HEAVANS NO!!!!!!!!!!!!!!!!!!!!!!!