Thread: I Need Lots of Tall Deck BBC Info

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Originally Posted by pat mccarthy

well i do not think the head will fit to good on the new block you will need to get the right head gaskets and check up by the valley to make srue it this not weak on the seal where the water runs thru the deck

O.K., now I am confused.What series is the block?

Gen.V Eric....and I think your estimates and equipment recommendations are right on. Except maybe for the heads. Will they work on a Gen V block? Otherwise, the 781's are a good choice, or 049's if you come across them...same head basically. John

Originally Posted by 1JohnnyO

Gen.V Eric....and I think your estimates and equipment recommendations are right on. Except maybe for the heads. Will they work on a Gen V block? Otherwise, the 781's are a good choice, or 049's if you come across them...same head basically. John

The 781's will not fit on Gen V or VI blocks.
The 920 heads will work.They come with 2.19,1.88 valves.The port volume on these heads is 325 and they to be converted to run an adjustable valve train.
Maybe some day I will learn to read a little better.

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Wow....Maybe that block wasn't such a good deal...seems like nothing 'normal' will work with it...then there are the fitment issues...I think I would have an ad in the want ad digest by now. I'll stick with the old Mk IV blocks, those are the ones I know best! Good luck at any rate, Im sure it will be a beast. John

What should I expect to pay for a good 4-Bolt low deck block, a stroked low deck may be the way to go with the vette project. Does anyone have any suggestions for a good place to score an assembled short block, or will it be cheaper to build it myself.

How many cid can you stroke a low deck to?
Is the max stroke still 4.375?
How much torque will I be losing by going with the low deck with about the same cid?

Well, my 505 is a 4.350 (.100 over) and 1/4" stroke. I got my 4 bolt block for 100 bucks...dont plan on that happening too much, I sorta fell into the deal. It was available at my machinist's shop. He claims he goes up to .125 all the time on MK IV blocks...but they have to be sonic checked first to be sure. 1/4" stroke is really easy, but I doubt that 3/8" would be so easy, if it's even possible. I had to do a tiny bit of grinding at the bottom of some of the bores, just to be sure. The rod bolts came pretty close on some of them. Otherwise, it went together without a hitch. As far as building it yourself, it might be cheaper, it might not. And it depends on how much you like getting into it. I personally love doing it myself. Competition Products has a 496 assembled short block for $3595.00, not bad !! Im not sure of the max cubes on a std. deck short block. I would bet it's about what Im at, 505...not many machinists want to go to .125, but if you did, you would be at, Im not sure!! Maybe 512, 511 ?? Pat will know these figures, he does it all the time. John

did you read any thing i posted

Pat, now Im curious....what other mods did the Mk IV block require to take a 3/8" stroker crank? I thought about doing that, but too many people told me it was a real pain to prep the block. Bottom of cyls? How about clearance between the cam and rod ends? John

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Originally Posted by pat mccarthy

did you read any thing i posted ? page 2 . 4.320 bore 4.375stroke =513 short deck. you do not need a four bolt main i have done over 40+ builds with out four bolt mains over 650+hp it would be nice to have , i have blocks right now to build any thing from 468 to 588 short deck .or 572 to 638 would be tall deck if you want some thing you can e mail me .i have built many big blocks. yes jonnny O you are rigth .0125 is a big move it would be1/2 full of block rock if i did it . but i did have ?one 454 i had to thick sleeve and bore it to 4.500 and there was still some wall there .not to say one would go that far but ?4.440 and some block rock fill to the top some blocks can take a 0125 bore but that is not many and the new mark5-6 i would not go past .060 on them less it is a 502 block and still that alot for them to

When I use to bracket race I had a 468 with a 2-bolt main and an ARP stud kit.I shifted at 6,600.Every winter when I would pull it down to re-ring it the caps where still very tight.After the 3rd. season on it I had to do a very small amount of line honing.On the street it would last damn near forever.

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Well now, this gives me ideas for a winter project. I have 2 MK IV blocks sitting in the garage. I have a lot of pistons and rods. I have a couple sets of heads. (and another set coming at the end of Sept!! I need help!!! Cant stop buying!!! ) HHmmmm....I think the 3/8 stroke is probably the biggest I would tackle. But maybe with a little help (Pat?? ) Gets me thinking.

Originally Posted by 1JohnnyO

Well now, this gives me ideas for a winter project. I have 2 MK IV blocks sitting in the garage. I have a lot of pistons and rods. I have a couple sets of heads. (and another set coming at the end of Sept!! I need help!!! Cant stop buying!!! ) HHmmmm....I think the 3/8 stroke is probably the biggest I would tackle. But maybe with a little help (Pat?? ) Gets me thinking.

One thing to consider is the piston availabilty is much better with the 496.