[J Druin]

Have a chance to buy a 67 YH 428 block only with no caps. Seller has several caps I can take and see if my machinist can match up close enough to be honed. I do not think he has any 4 bot caps but for my use no real need. He also has a 4" crank that has been turned .020 on both mains and rods. He wants $400 for both with the understanding of being able to hone the block. What do you guys think.

[The Boss]

I have a set of 4 bolt caps if you need them. Close or not, you'll need to have the block line bored.

[J Druin]

Was told by Butler you should not line bore stock caps, he said if you get caps that are close (within maybe .002 or .003) you can hone it.

[RamAirIV28]

According to Rocky's book several vendors sell replacement caps.

but still......

I wonder what a 428 with 4 bolt mains is worth? I just bought one, a 1969 4 bolt main complete with ARP studs and standard bore for 500 bucks from Pontirag in AZ

[GTOLou]

Originally Posted by RamAirIV28

According to Rocky's book several vendors sell replacement caps.

but still......

I wonder what a 428 with 4 bolt mains is worth? I just bought one, a 1969 4 bolt main complete with ARP studs and standard bore for 500 bucks from Pontirag in AZ

That is a great deai - getting one without any main caps will run up your machining costs. I am not so sure that 400 bucks for the OP to pay for a bare block with some loose, non-fitting caps is really that great a deal.

[hurryinhoosier62]

Originally Posted by J Druin

Was told by Butler you should not line bore stock caps, he said if you get caps that are close (within maybe .002 or .003) you can hone it.

I've align bored several thousand blocks. IF you can find a set that close, it would still need to be align bored. Funny, as thick as Pontiac caps are I would see no problem align boring them.

[ANDYA]

I would avoid a block that is missing the original rear cap. Even if you could find a cap that fits close enough to align bore/hone I would be worried that the rear main seal would always leak. Every once in a while you see a standard bore block for sale missing all five caps and bolts and I can't figure out why someone would separate them from the original motor. IMHO, better off to pass on it and find a complete block.

[J Druin]

Sorry, I must have miss understood what Butler was telling me. No problem to align bore but I guess he was saying if I get close enough with the caps I may be able to just hone. Anyways sounds like it may be more trouble than its worth.

[hurryinhoosier62]

Originally Posted by J Druin

Sorry, I must have miss understood what Butler was telling me. No problem to align bore but I guess he was saying if I get close enough with the caps I may be able to just hone. Anyways sounds like it may be more trouble than its worth.

In my experience, the chances of finding a set of main caps that would fit close enough to align hone is about 1 in 100. I had 200 sets of 6.2/6.5 GM caps. 1 out of 100 set would fit close enough (.002-.003) to hone. Everything else would have to be align bored.

[KO]

the best way is to used oversize dowels so you can move the caps wherever needed

[hurryinhoosier62]

Originally Posted by KO

the best way is to used oversize dowels so you can move the caps wherever needed

WHAT? I use SBC head dowels when machining Pontiac mains. They're .003 oversize and it has ZERO effect on realigning the main bore/main caps.

[428GTO70]

Originally Posted by hurryinhoosier62

WHAT? I use SBC head dowels when machining Pontiac mains. They're .003 oversize and it has ZERO effect on realigning the main bore/main caps.

I'm pretty sure he is talking about removing the factory dowels and bolting on the non matching caps as close as possible to where it fits the best in regards to the bore, and from there you carefully tighten the bolts to hold them in place taking great care that they do not move. Then you enlarge the dowel holes in the cap and the block to accommodate a larger dowel.

Now the non matching caps are a lot closer and can be align bored much easier, possibly honed

I had to do this on my 428 block when I replaced my number 1 cap because of a crack and installed aftermarket 4 bolts caps.

[hurryinhoosier62]

Originally Posted by 428GTO70

I'm pretty sure he is talking about removing the factory dowels and bolting on the non matching caps as close as possible to where it fits the best in regards to the bore, and from there you carefully tighten the bolts to hold them in place taking great care that they do not move. Then you enlarge the dowel holes in the cap and the block to accommodate a larger dowel.

Now the non matching caps are a lot closer and can be align bored much easier, possibly honed

I had to do this on my 428 block when I replaced my number 1 cap because of a crack and installed aftermarket 4 bolts caps.

OK? Sounds like a LOT of work when you can install aftermarket BILLET caps MUCH easier.