Advice needed on LQ9 swap for LS1

**Firebirdjones** · 04-21-2010, 12:37 PM

Originally Posted by Hi-Po

There are a few companies out making LS2 6 bolt blocks. Running deep into the single digits as well. An aluminum block shouldn't be taken out of the running for big power. This engine should see upwards to 2000 HP when its done

6 Bolt LS2

Ya, that's aftermarket. It should be plenty strong.
I was talking about aluminum stock production blocks.

**JRENIGAR** · 04-21-2010, 02:19 PM

^^^ I say damn!!! How much???

**Firebirdjones** · 04-21-2010, 02:48 PM

Originally Posted by JRENIGAR

^^^ I say damn!!! How much???

I'm going to say close to ZL1 price territory

**JRENIGAR** · 04-25-2010, 07:27 AM

12k??? f-that. thats an expensive 85lb diet!!!!

**Firebirdjones** · 04-25-2010, 08:45 AM

Originally Posted by JRENIGAR

12k??? f-that. thats an expensive 85lb diet!!!!

Oooof,,,that bare block is $12K??? Well I stand corrected,,,,that's 3 times more than the ZL1 aluminum block then,,,,,OUCH!!!

Go cast iron. Find 65 lbs. somewhere else.

**MudStainKILLA** · 04-25-2010, 10:40 AM

IMO go with the lsx block, so many options and roads that you can take. 6 bolt heads for about 2400, and ive found em as low as 1900. Granted you are picking up some wieght there but if you are looking to put 850 horses on the deck are you really worried about the extra wieght of that block? And if you are like jones states above, find the wieght somewhere else

**JRENIGAR** · 04-26-2010, 04:38 PM

^^^ 12k??? IDK I guessed thats about what the complete engine was, I miss understood. Still 3-4k for a block??? Nah, Just a regular fool here, not a damned fool....

**wormus** · 05-17-2010, 04:42 AM

Originally Posted by Firebirdjones

I agree on the 243's, for a large cube motor and forced induction I'd jump to something better.

As for the extra head bolts,,,,,,I am thinking that's only available on the aftermarket LSx blocks. Factory production blocks don't offer that if memory serves.

Thanks. The engine is going back together nicely but I have doubts about the heads on my old setup. Comparing 2 graphs running 12psi and 15psi, mid range torque jumps by 170lbs to 920lbs at 3500rpm but drops steeply as rpm rises. The net result is I end up with the same power by 6500rpm. The cam has been changed for more grunt but I would have expected more boost to turn into more power further up the rpm range? Could this be cam profile or are the heads holding me back? Which heads should I go for on the LQ9, I'm thinking of these:

**edit out links**

I assume both will fit a 4" bore? Don't want to spend loads of money if I'm only going to gain 10whp so appreciate advice.