Rectangular or Cathedral give me your .02

**2000dreambird** · 09-19-2010, 10:55 AM

i need to replace the heads and will be doing a cam, need some dif opinions of what heads you think are better or worst and why...

**9T8W66** · 09-19-2010, 04:54 PM

For the money a stock set of rectangle ports (L92/LS3) are tough to beat but unfortunately they won't work on anything smaller then a 4.00" bore block (6.0).
So unless your thinking about going with a larger shortblock stick with the Cathedral port heads.

**c5z28** · 09-19-2010, 04:59 PM

They make a set for the l92's to fit on our cars I have heard of. Wouldn't be cost effective like they are on the ls-2's

**blackbirdbrain89** · 09-21-2010, 04:29 PM

Originally Posted by 2000dreambird

i need to replace the heads and will be doing a cam, need some dif opinions of what heads you think are better or worst and why...

why do u need to take the heads off for a cam swap?

**2000dreambird** · 09-22-2010, 12:07 AM

Originally Posted by blackbirdbrain89

why do u need to take the heads off for a cam swap?

I schooled a kid in a BMW but when I got home I had a knocking noise in my top end. I think it's a lifter. So if I have to take the heads off I might aswell change them and if I'm going to change them I might aswell cam it too.

**9T8W66** · 09-22-2010, 03:59 PM

Originally Posted by 2000dreambird

I schooled a kid in a BMW but when I got home I had a knocking noise in my top end. I think it's a lifter. So if I have to take the heads off I might aswell change them and if I'm going to change them I might aswell cam it too.

I'd be willing to bet the noise is from bent pushrods (cheap fix). Do a search as this is a pretty common problem encountered on manual trans cars.
It only takes one blown shift to bend a couple pushrods.

**2000dreambird** · 09-23-2010, 12:04 AM

Originally Posted by 9T8W66

I'd be willing to bet the noise is from bent pushrods (cheap fix). Do a search as this is a pretty common problem encountered on manual trans cars.
It only takes one blown shift to bend a couple pushrods.

I already pulled them ut and checked them they all look good.

**Smittro** · 09-23-2010, 02:57 AM

Originally Posted by blackbirdbrain89

why do u need to take the heads off for a cam swap?

Because unless you have a way of holding up the lifters you'll have to remove the heads to get them out on ls1..

**rooster18** · 09-24-2010, 08:56 AM

Originally Posted by Smittro

Because unless you have a way of holding up the lifters you'll have to remove the heads to get them out on ls1..

lifters are simple to hold up without pulling the heads. simply spin the cam over by hand backwards and forwards and insert 2- 5/16" rods in the two holes behind the water pump when you get that far along and wa-lah. but if you're gonna wanna do heads anyway then go for it

**shady milkman** · 09-24-2010, 09:00 AM

by far the rectangular port heads are a better platform...however you are stuck with cathedral unless you want to spend stupid cash on a mast small bore rectangular head.

if you got the cash..get a good set of 205 AFRs

**Smittro** · 09-24-2010, 09:01 AM

Originally Posted by rooster18

lifters are simple to hold up without pulling the heads. simply spin the cam over by hand backwards and forwards and insert 2- 5/16" rods in the two holes behind the water pump when you get that far along and wa-lah. but if you're gonna wanna do heads anyway then go for it

Ah ha, I see..

**LSXZ28** · 09-25-2010, 02:51 PM

I would go with a Texas Speed Torquer V2 cam and 5.3L heads package... can't beat the bang for the buck there!

**El Toro Loco** · 09-25-2010, 03:00 PM

In the GM high tech performance, where they showcased a black formula built by hawks third gen it states the placed some l92 heads on the ls1 how is that if theyare made for 6.0 n up engines I didn't understand that

**c5z28** · 09-25-2010, 05:37 PM

Originally Posted by El Toro Loco

In the GM high tech performance, where they showcased a black formula built by hawks third gen it states the placed some l92 heads on the ls1 how is that if theyare made for 6.0 n up engines I didn't understand that

It's a kit they make

**shady milkman** · 09-25-2010, 06:33 PM

Originally Posted by El Toro Loco

In the GM high tech performance, where they showcased a black formula built by hawks third gen it states the placed some l92 heads on the ls1 how is that if theyare made for 6.0 n up engines I didn't understand that

Along with what c5 said...you can run a gen iv head on a ls1...but it will suffer in terms of performance..as there will be shroading and the valves are quite large for a 346 and will require a split cam...so they say

**turbols1317** · 09-25-2010, 11:46 PM

Originally Posted by 2000dreambird

I schooled a kid in a BMW but when I got home I had a knocking noise in my top end. I think it's a lifter. So if I have to take the heads off I might aswell change them and if I'm going to change them I might aswell cam it too.

good shit... my buddy had a bad ass knocking noise from somewhere under the hood in his 99 m6 ta... sounded like a couple rods knocking. so we got tired of hearing it and he got pissed. we did a 1st-4th WOT pull and it has never made any other noise than what a normal car should make.. fixed itself.. lmao. just saying.....

**2000dreambird** · 09-27-2010, 12:07 AM

Originally Posted by LSXZ28

I would go with a Texas Speed Torquer V2 cam and 5.3L heads package... can't beat the bang for the buck there!

This is one of the setups I'm interested in ..

**El Toro Loco** · 10-01-2010, 12:17 AM

Originally Posted by shady milkman

Along with what c5 said...you can run a gen iv head on a ls1...but it will suffer in terms of performance..as there will be shroading and the valves are quite large for a 346 and will require a split cam...so they say

glad to clear that up i jus had remember reading that it could not be made to fit then i read that article and was like wtf i thought it couldnt be fit, they also supercharged that formula that was a sick 3rdgen

**'02 WS6** · 10-01-2010, 03:29 AM

The GMHTP article was using Gen IV L92 heads from Mast Motorsports and were made specifically for a stock bore LS1. Factory L92s are made for a 4.000" bore, not the LS1s 3.910. You cannot go buy some L92s off a wrecked Vette, G8, etc etc and slap 'em on an LS1.

That said, just because rectangular is the new fad doesn't necessarily mean its the best option. Ask Pat G why he went with his cathedral Mamo'd AFRs over his worked L92s on his G8, and is almost 25-30rwhp higher than other H/C G8s that have worked and heavily worked L92s.

**shady milkman** · 10-01-2010, 05:24 AM

Originally Posted by '02 WS6

The GMHTP article was using Gen IV L92 heads from Mast Motorsports and were made specifically for a stock bore LS1. Factory L92s are made for a 4.000" bore, not the LS1s 3.910. You cannot go buy some L92s off a wrecked Vette, G8, etc etc and slap 'em on an LS1.

That said, just because rectangular is the new fad doesn't necessarily mean its the best option. Ask Pat G why he went with his cathedral Mamo'd AFRs over his worked L92s on his G8, and is almost 25-30rwhp higher than other H/C G8s that have worked and heavily worked L92s.

rectangular ports are still relatively new. The cathedral ports were the same for a good amount of time when they first came out...