Saber-1

I need assistance with determining if I can fit an LS 454 tall deck into my 2017 Chevy SS sedan. If anymore knows the girth of a tall deck LS 454 vs. a LS 427 standard deck, that would be helpful.🤷‍♂️

grubinski

I don’t know what the difference in height of the deck is between the tall and normal blocks. Let’s call it ‘h’. Since the decks are at 45 degrees to horizontal, the width between the outside edges of the left and right side cylinder heads will increase by 1.414*h when the deck height increases by h.

bthomas

iTrader: (1)

Tall deck is basically a 1/2” taller deck. 9.24” to 9.75”
can’t imagine the widths being more than an inch wider ea side from the taller deck.

Saber-1

Thank you for the useful information. Can you help me with the formula result?

h: 9.240” std deck
h: 9.750” tall deck

Double06

iTrader: (1)

As far as manifold height if you use the spacers the heads will go further out and the block itself will be about .7 inches wider corner tip of block on each side. The bolt holes for the heads are pushed out/up 1/3 of an inch. Think of it as a 45 degree triangle and the 1/2 inch is the long end the two short ends are 70% or so of that. The height as it related to manifold get tricky as it drops in the V Cradle. One would think it would be another .35 of an inch to get back to the other direction for the manifold to fit. The tall manifold spacers I think are 1/2 and inch thick but once again at angle. This would indicate .7 inch in total height (.35 + .35) but I have seen engine builders say it is 1/2 inch taller at manifold. For example on C6 Corvette tall deck guys run the 3/8 shorter engines mounts and then shim the cradle a little to get the body up a little.

grubinski

Double06 nailed it .... (1.414 * (9.75-9.24)) ==> .72" wider overall for the taller block.

TrendSetter

hpr sells a short deck 468.

gnx7

iTrader: (28)

Just remember you will also need custom headers Tall deck isn't really worth it unless you have a max effort setup.

Saber-1

Thank you to grubinski and Double06 for the very helpful information.