Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com - View Single Post - LLT heads on an LFX short block... Doable? Worth it?

Jason@JacFab · 08-12-2014, 04:52 PM

I'm think that the LLT heads will bolt onto an LFX... The 10-11 LLT, and 12+ LFX both use the same head gasket, which tells me for mounting/oiling/cooling purposes, they are probably identical.

It seems the MACE cam's don't work so hot in the LFX supposedly because of it's single exhaust outlet? Not to mention you don't get the cool cam sound. The LLT engined cars just seem to sound better than the LFX cars in general.

To sum it up, potentials gains are:

Headers (more power?)
Better sound (w/ and w/o headers)
Cams available (more power? cool sound)
Maximized porting area on the ex side.

What potential losses could be suffered from this swap? I can only think of two off the top of my head...

1) The LFX got a slight compression bump over the LLT. 11.3 on the LLT vs 11.5:1 on the LFX. I am not certain if this was a result from changing the shape/size of the combustion chamber, or if it was simply just the pistons

2) The LFX has larger intake valves. 38.3 mm vs. the LLT's 36.96 mm. This should be an easy fix by just installing the LFX intake valves.

I think the only thing that might screw a guy on doing this is if the injectors, fuel rail, and HPFP are so different between the two that you had to run the LLT stuff also, which would add additional cost to the swap.

Thoughts?

(ps: I scored a set of LLT heads with a fresh valve job today...)

08-12-2014, 04:52 PM	#1
Jason@JacFab Drives: 2016 1LT RS Camaro; 72 Chevelle Join Date: Apr 2008 Location: Central Point, OR Posts: 5,685 View My Garage	LLT heads on an LFX short block... Doable? Worth it? I'm think that the LLT heads will bolt onto an LFX... The 10-11 LLT, and 12+ LFX both use the same head gasket, which tells me for mounting/oiling/cooling purposes, they are probably identical. It seems the MACE cam's don't work so hot in the LFX supposedly because of it's single exhaust outlet? Not to mention you don't get the cool cam sound. The LLT engined cars just seem to sound better than the LFX cars in general. To sum it up, potentials gains are: Headers (more power?) Better sound (w/ and w/o headers) Cams available (more power? cool sound) Maximized porting area on the ex side. What potential losses could be suffered from this swap? I can only think of two off the top of my head... 1) The LFX got a slight compression bump over the LLT. 11.3 on the LLT vs 11.5:1 on the LFX. I am not certain if this was a result from changing the shape/size of the combustion chamber, or if it was simply just the pistons 2) The LFX has larger intake valves. 38.3 mm vs. the LLT's 36.96 mm. This should be an easy fix by just installing the LFX intake valves. I think the only thing that might screw a guy on doing this is if the injectors, fuel rail, and HPFP are so different between the two that you had to run the LLT stuff also, which would add additional cost to the swap. Thoughts? (ps: I scored a set of LLT heads with a fresh valve job today...) Last edited by Jason@JacFab; 08-14-2014 at 11:00 AM.