High deck vs Low deck blocks
 

Anyone have info on the dif?
How do they compare? :eek:

RE: High deck vs Low deck blocks
 

My friend had one in his street rod. Very limited in the aftermarket parts when rebuilding it. He said he'll never do that again for what its worth.

RE: High deck vs Low deck blocks
 

You're referring to the "high deck", right?
I know absolutly nothing about them, only heard of them.

RE: High deck vs Low deck blocks
 

High deck from what I hear - are usually in pickup trucks and the like and are not good donors for our cars due to clearance issues.

[sm=icon_cheers.gif]

RE: High deck vs Low deck blocks
 

are the high decks of later production? the big three all produced higher deck blocks in later years(late '70's on)for emissions. if they are like others they can be milled to be like earlier models. What is the actual differance in hight? Cheers

RE: High deck vs Low deck blocks
 

While looking at intake manifolds on the net, is where i came across the designation "High Deck". I'm guessing the the cyl would be deeper, allowing a longer stroke. More torque? Hmmm.......:eek:

RE: High deck vs Low deck blocks
 

I cant remember exactly but i think the tall deck blocks are 6 hundredths of an inch longer stroke.
the intakes are different for sure.
I checked crank prices etc and it seems you can buy a steel fordged crank for a tall deck for under 200 alot cheaper than a standard deck steel crank but the longer rods needed to use a performance type piston (for rodding one) are a little pricey.
head and valve cover clearances can be an issue, even more so for a vette.
I have a 68 Marine 427 tall deck block. and supposedly the cylinder walls are a bit thicker as well for heavy duty useage.

RE: High deck vs Low deck blocks
 

Been doin' a little research, and here's what I have come up with from a few dif sources.......

"A typical BBC is limited to about 509 ci. The after market tall deck BBC's have a practical limit of about 632 ci."[/align][/align]"Look for 'em in 2 ton and bigger trucks, school busses, etc. The easiest way to tell is to check the distance from the top water pump hole to the deck of the block. If it's about 1/2" or so, it's a standard/passenger block. If it's more like 3/4", it's a truck block. They use 2 thermostats as well, makes for a screwey looking t-stat cover. They're ALL 4-bolt blocks."
[/align]"...estimate is 475HP @5000, and ~600lbs-ft of torque at 3000, with torque exceeding 500 lbs-ft from 2000 to 4500."[/align][/align]".... pin your eyeballs to the back of your head any time you step on the go-pedal... "[/align][/align]"Combination is as follows:
427 tall-deck BBC, bored .060"
4.5" stroke, 6.7" rods, forged pistons, ARP studs and H-beam rods, internally balanced.
My calculations indicate the TDC will be .020" below the deck height, -3cc valve relief.
I just scored a set of 290 large-oval heads, 2.19/1.88 valves, ported and blended bowls (for $350), ready to run. 106 cc chambers (polished).
With a .039" compressed-thickness head-gasket, I come up with (IIRC) a static compression ratio of 9.8:1."
[/align]Sounds like a killer platform to build on. Only draw backs,are that it would be a PITA to install in a C3. Forget your stock hood, and figure on using a custom exhaust. Apparently the brake booster would need to be changed to a smaller diameter.[/align]

RE: High deck vs Low deck blocks
 

I have to admit that I always loved the feel of a big block (Chevy), especially in something with some bigger gears, like 4:88s, at the top of 3rd. gear (with a 4-speed). This is when you catch and blow byall the small block ie; 340 Darts and Dusters that took you out of the hole. I also know that you can spend alot less money and build a small block (Chevy) to run damn near as good as the big block. (both built). Ofcourse the two have very different feels. Lately, with the great parts you can get fora 350using the 3.75" stroke (400)crank , easily over 500 horse power, and streetable, I feel that not just money-wise, but horse power and now that you mention it, clearance in the engine compartment and under the stock hood (probably have to put a small bump in it LOL),also consideringthe car will corner and over all handle better with a small block, I'm inclined towant a 383 over a big block.
Just a thought, "not trying to start more **** LOL" and also know and have to consider that all three are very different animals. ( the big block, the 350 w/ the stock 3.48" stroke crank, and the 350 w/ the 3.75" stroke (400)crank.)

RE: High deck vs Low deck blocks
 

Hi there starship,I do have a tall block 427 in my 38ft. school bus/RV. Good solid torquey engine. The biggest differance is the intake. Because of the taller block and longer stroke the geometry between the heads and block are totally different to the standard block 427. Also physically you need more room in the engine compartment. Nice engine,but better off going to the standard 454. I found it much easier to get all the goodies and mods forthe 454and alot less headaches to get into my C3.