mguidry629

iTrader: (6)

I'm looking at a deal on an LT4 setup. The guy bought the LT4 conversion with heads, intake, hotcam kit, etc.

http://www.jegs.com/i/Edelbrock/350/7109K/10002/-1

The heads on the link are 195cc intake runner and I read somewhere that the stock LT4 heads were like 185cc. I guess one is an original GM head and the other is an aftermarket GM Performance brand head. Maybe someone can explain that, but that's not my main question.

Can these LT4 heads be ported and what's the potential there? I don't see much advertising of ported LT4 heads. How does the 'as cast' LT4 compare to a ported set of 195cc LT1 heads (like the LE1)?

Anyone have experience with LT4 heads or more specifically porting LT4 heads? How many cc's can you get the intake runner and what's the flow and power potential?

ahritchie

iTrader: (1)

I'm don't know much about the LT4 heads other than they flow slightly better than LT1 heads with bigger valves, I do know however the best place to get them ported is Ai. They have a 195cc version and 215cc version worth 20HP over equivalent ported LT1 heads.

http://advancedinduction.com/LTX/AiLTx195ccLT4.php

http://advancedinduction.com/LTX/AiLTxLT4CompHead.php

Nastyc4

iTrader: (13)

POtential in almost any head is your wallet. I use LT4 Heads and will make close to 600 HP NA and spin 8k+ rpms. Is there a better head? yes many of them. WHy did I use LT4? Because if I wanted a better head I would build a gen 1 sbc with 12 degree heads and a huge bore and a sheetmetal intake and make serious power. I already had the LT4s and I decided to just see what the most power I could get out of an LT4 Head/intake setup was.

moehorsepower

iTrader: (3)

My LT4 were ported to app 205cc and with forced induction made 722 RWHP, looking for 800 with a turbo setup..

gregrob

iTrader: (8)

AI is better

mguidry629

iTrader: (6)

So it looks like there is room for improvement with the LT4 head (205cc+) which answers one of my questions.

I'm not trying to compare the LT4 heads to any other aftermarket heads, I'm trying to get answers on the comparison to a 195cc LT1 ported head.

Here's a more direct question: if I get the LT4 heads with my combo below, should I just bolt them on and go, just clean up the runners and valve guide areas, or go all out port job trying to get to 205cc?

383, 12:1 CR, LE custom cam 232/242 @.050, .578/.576 lift, supporting valvetrain, ss3600 stall, 3.73 gears + all the supporting bolt ons.

Looking to spin to about 6500rpm. I've got a few sets of stock LT1 heads laying around and I've ported stock heads to 190-195cc, but it's time consuming so I'm just weighing my options.

I'm going to get the LT4 setup from this guy either way because it's a good deal and even if I don't use them, I can flip them and make a few dollars.

mguidry629

iTrader: (6)

Never heard that one before No one is disputing that. I'm sure their 200cc CNC'd LT1 heads are better than a LT4 cast head.

Nastyc4

iTrader: (13)

yeah I think a mildly ported LT1 head will kill an LT4 head. as cast they are a better base to start with but when comparing ported heads to an lt4 I wouldnt bother.

raymond mckinney

iTrader: (4)

Stock LT1's flow around 215cfm, stock Lt4's flow around 260ish. Ported LT1's can flow 270-285ish and LT4's can flow 300cfm.

mguidry629

iTrader: (6)

Thanks guys, I think that answers my questions. I'll use the LT4 heads and port them to 200cc-205cc and aim for about 265-270cfm. That should be plenty for my combo.

speed_demon24

iTrader: (6)

Or you could save yourself a ton of $$ and get ported LT1 heads that would surpass your goals.