Tall deck blocks vs. standard deck blocks: What the difference?
Thread Starter
Racer
Joined: Aug 2001
Posts: 445
Likes: 2
From: Austin Texas
Tall deck blocks vs. standard deck blocks: What the difference?
Is this the same as a Mark IV block (standard) vs. a newer Mark V block (tall)?
I'd be grateful if someone could clear this up for me.
Regards,
Bryan
I'd be grateful if someone could clear this up for me.
Regards,
Bryan
Instructor
Joined: Jan 2005
Posts: 117
Likes: 0
From: OKLAHOMA CITY OKLAHOMA
Originally Posted by 300ZXTwinTurbo
Is this the same as a Mark IV block (standard) vs. a newer Mark V block (tall)?
I'd be grateful if someone could clear this up for me.
Regards,
Bryan
I'd be grateful if someone could clear this up for me.
Regards,
Bryan
Instructor
Joined: Jan 2005
Posts: 117
Likes: 0
From: OKLAHOMA CITY OKLAHOMA
Originally Posted by 300ZXTwinTurbo
Is this the same as a Mark IV block (standard) vs. a newer Mark V block (tall)?
I'd be grateful if someone could clear this up for me.
Regards,
Bryan
I'd be grateful if someone could clear this up for me.
Regards,
Bryan
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
Tall decks are a pain in the butt and don't lend themselves well to cars with limited engine space. Since the decks are taller, exhaust ports end up being raised about .250". You'll need a special manifold and distributor plus custom brackets. Best bet if you have one is to find a drag racer to sell it to and find a standard deck block to use instead. Drag racers like 'em because they have great rod:stroke ratios and they're all 4-bolt main blocks. If you don't need the crankcase area for a big stroke, don't use one. HTH
Thread Starter
Racer
Joined: Aug 2001
Posts: 445
Likes: 2
From: Austin Texas
Jim - Thanks for taking the time to help me come up with answers.
Perhaps I should have phrased the question a bit different. The big block in my vette is a Mark IV block, that much I know. Now, I have no idea what block came with my GM 502 crate motor'd Camaro.
Any thoughts as to which block came with the 502?
Thanks all.
Bryan
Perhaps I should have phrased the question a bit different. The big block in my vette is a Mark IV block, that much I know. Now, I have no idea what block came with my GM 502 crate motor'd Camaro.
Any thoughts as to which block came with the 502?
Thanks all.
Bryan
Race Director
Joined: Feb 1999
Posts: 16,978
Likes: 7
From: In Dreams There Is Truth Ohio
Originally Posted by 300ZXTwinTurbo
Now, I have no idea what block came with my GM 502 crate motor'd Camaro.
Any thoughts as to which block came with the 502?
Thanks all.
Bryan
Any thoughts as to which block came with the 502?
Thanks all.
Bryan
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Instructor
Joined: Jan 2005
Posts: 117
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From: OKLAHOMA CITY OKLAHOMA
the 502 (8.2 liter)big block part # 10185085 has a short deck 4 inch stroke like the 454 but a lager bore 4.466. only available thru GM perf parts. first produced in 1970
Last edited by jimvette74; Apr 8, 2005 at 12:20 AM. Reason: add info
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
Originally Posted by L88Plus
Tall decks are a pain in the butt and don't lend themselves well to cars with limited engine space. Since the decks are taller, exhaust ports end up being raised about .250". You'll need a special manifold and distributor plus custom brackets. Best bet if you have one is to find a drag racer to sell it to and find a standard deck block to use instead. Drag racers like 'em because they have great rod:stroke ratios and they're all 4-bolt main blocks. If you don't need the crankcase area for a big stroke, don't use one. HTH
Burning Brakes
Joined: Apr 2003
Posts: 844
Likes: 0
From: Central KY
Originally Posted by 300ZXTwinTurbo
Perhaps I should have phrased the question a bit different. The big block in my vette is a Mark IV block, that much I know. Now, I have no idea what block came with my GM 502 crate motor'd Camaro.
Any thoughts as to which block came with the 502?
Any thoughts as to which block came with the 502?
Instructor
Joined: May 2001
Posts: 228
Likes: 0
From: Santa Cruz CA
I am building a tall-deck Dart block with a 4.5" crank. 580ci now but can be overbored to as much as 605ci. Haven't installed it yet, but I know the headers will need to be reworked and I will probably have firewall to valve cover clearance issues. I machined the flange off the tach-drive distributer and am using a split-coller in its place so that's no problem. Not sure what to do with the hood yet, but I don't plan on installing it until mid-summer so I have plenty of time.
Race Director
Joined: Feb 1999
Posts: 16,978
Likes: 7
From: In Dreams There Is Truth Ohio
Originally Posted by After Shark
502 is a gen Vi Block
Last edited by GDaina; Apr 8, 2005 at 12:42 PM.
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Mark IV has boss for mechanical fuel pump.
Gen V, no fuel pump boss, one piece rear seal. Different water passages to heads.
Gen VI Changed thw water passages to use Mark IV heads. Machined for roller lifeters. Identified by new 6 bolt aluminum timing cover.
Tall 10.2", short 9.8.
Your 502 will be a short deck. There were a few Mark IVs, mainly in marine applications, but most likely Gen V or VI.
Gen V, no fuel pump boss, one piece rear seal. Different water passages to heads.
Gen VI Changed thw water passages to use Mark IV heads. Machined for roller lifeters. Identified by new 6 bolt aluminum timing cover.
Tall 10.2", short 9.8.
Your 502 will be a short deck. There were a few Mark IVs, mainly in marine applications, but most likely Gen V or VI.
Burning Brakes
Joined: Jul 2002
Posts: 1,136
Likes: 100
From: Nova Scotia
Originally Posted by 68427
I am building a tall-deck Dart block with a 4.5" crank. 580ci now but can be overbored to as much as 605ci. Haven't installed it yet, but I know the headers will need to be reworked and I will probably have firewall to valve cover clearance issues. I machined the flange off the tach-drive distributer and am using a split-coller in its place so that's no problem. Not sure what to do with the hood yet, but I don't plan on installing it until mid-summer so I have plenty of time.
