GeoMetricMoving

Just bought the block, looking to order the rotating assembly from Callies. Have a few questions on intakes and heads. My two picks would be Holley "Hi-Ram" LS7 or Mast 4500 LS7 EFI intakes? Heads, RHS Pro-Elite 291 LS7 or Mast Black Label LS7 305cc heads?

Going with either a Pro Charger or Vortec.

Any opinions and experiences?

BLOWNBLUEZ06

iTrader: (17)

You're doing a 454 LSX block? Unless they changed their tune with the next generation blocks, it's not recommended with any significant level of boost. Besides, you can make up for less C.I. with more boost.
MAST heads with upgraded springs and inconel valves. The Holley Hi Ram intake is a nice piece and all things considered would be my choice.

GeoMetricMoving

Really? I see 454 & 427 LSX engines blown all over the Internet for sale. Where have you read this?

Thanks,

Ron

6togo

iTrader: (13)

The cylinder walls on a lsx 454 get to thin for allot of boost there was a guy that had one split a cylinder and even though GM said boost was ok they were not going to warranty it i think they finally did due to bad press but i could be wrong!

GeoMetricMoving

Yes, I have read his bashing posts all over the Internet. But, do we really know what happened? There are so many factors that could have lead to his engine failure. I see many Engine shops selling turbo and supercharger 454 LSX engines, maybe I will call a few to hear their opinion?

GeoMetricMoving

This rotating assembly is perfect for those looking to build a big-inch engine using the GMPP LSx or RHS LS 9.70" tall-deck engine block that want to use a power-adder!

The tall-deck engine block allows for a longer connecting rod and lowered ring lands on the pistons, which make this setup ideal for large amounts of nitrous or boost!

http://www.texas-speed.com/p-1029-ts...-assembly.aspx

6togo

iTrader: (13)

Thats the way to go most agree 4.125 is about the limit on a std deck block for boost. Tall decks changes that for sure and yes we dont know the entire story with the other guy but why chance being #2 when you can either go a bit less Ci or do a tall deck and still make big power!

Blown06

iTrader: (32)

So one (1) fails and it will never work for anyone else ever again...........


We know how that turns out........

GeoMetricMoving

If you match part for part a smaller LSX motor to a larger ci 454, the larger engine will always win. Yes, you could boost 25lbs, and the 454 will boost 20lbs, to match HP, but how much sense does that make?

6togo

iTrader: (13)

Sounds like you have it all worked out and most big HP builds are done on smaller CI engines due to smaller stroke that spin easier have better placement of the rings. I'm building a LSX 427 for Twins on a std deck and all the builder i talked to say any bigger is really not needed and a potential for problems with walls getting thin or stroke bringing the piston to low in the bore causing wobble not the correct term but it beats up the skirts at higher rpm. I dont know what your goals are but unless you need
2Khp+ it might be money you dont need to spend.

ls1_chevelle

iTrader: (9)

agreed.

GeoMetricMoving

The twin turbo LSX 427 engines I have seen are all on tall deck blocks. I am only looking for 1000HP to 1300HP. and don't want 20lbs to get it. There are plenty of boosted 454 LSX engines out there, and only one that **** the bed.

GeoMetricMoving

427 LSX 9.7 Tall Deck Turbo

http://gmauthority.com/blog/2013/04/...pump-gasoline/

GeoMetricMoving

Here is another 427 boosted using the tall deck LSX block.

http://www.superchevy.com/technical/...bo_lsx_engine/

GeoMetricMoving

My block is not machined yet, I still have the option of using a 427 rotating assembly. Hmmm?

GeoMetricMoving

My mistake, this engine has a very short stroke building only 400ci in a LSX tall deck block.

If I was looking to punish my rotating assembly and block I would add crazy boost, but for what I need a 427ci or 454ci with moderate boost will last longer.

Unreal

I would stick with 427. RHS or All Pro heads would be great.

I'm running a 427 LSX livernois built shortblock with a maxed out Ysi. ~10k miles, no issues so far. They did revise the blocks recently as others have split them. I know a blue vette in texas split a cylinder at ~1200rwhp. If you have the newer revised block it should be ok.

GeoMetricMoving

Great news! I am leaning towards the 427 LSX Tall Block Version rotating assembly. Most likely Magnum or Dragonslayer crank.

6togo

iTrader: (13)

I can tell you i plan on making 1000whp with the std deck lsx 427 with twins at around 15psi talk with some of the big builders they will steer in the right direction. You really dont need a tall deck for your goals just added cost for othe parts to go with the tall decks.

Blackpanther99

iTrader: (8)

Im in for results. Rarely hear about 454LSXs being boosted due to a small walls.