[parish8]

Having choices in aftermarket castings is kind of new to the lt world. I don’t think there is much known about any of them but maybe some comparisons can be made to the same brand ls counter parts? Also there are some flow charts but not identical conditions so what is that worth?

The cid heads look cool. Here is a set from lme with flow numbers. Something like $5400 all loaded up. Ti and Inconel valves and good springs. https://www.latemodelengines.com/ind...lt4/cid-1.html


Here are some from mast. Pretty much the same price once loaded up. They are not 6 bolts like the cid heads but currently that is of no use. The flow numbers are down but i don’t know the test conditions. https://www.mastmotorsports.com/prod...-cylinder-head

Then the prc heads. They are more like $3000 but you can’t select an inconel exhaust valve. I called on this and the guy on the phone said it wasn’t even an option, that seems odd to me. I will be bouncing off the 2 step at times. I think I need the Inconel. https://www.texas-speed.com/p-9209-p...der-heads.aspx

Thoughts?

[KingLT1]

The CID heads were flowed on a larger bore(4.125) then a stock LT1/4(4.065) and If I had to guess the PRC and Mast were flowed on a stock bore. I also would like to see data for all lift ranges on the CID because the low lift numbers are equally if not more important.

That being said the PRC look really good for the money but I would agree on the Inconel valve for the exhaust. I kind of like the Mast heads with Stainless hollow intake and Inconel exhaust with polished dual spring kit. Shouldn't need any more valve spring then that unless you plan on going solid roller or really aggressive hyd cam.

[Joshinator99]

They’re all great options, IMO. Mast has a killer track record with the LS engines and I wanted to run something different, so that’s why I went with them. But all of those aftermarket heads run nice 3/4” thick decks too and flow well. Probably can’t go wrong with any of them.

[ZL1_2017]

Just purchased a set of CID Heads. Max effort fully loaded with incolnel valves and TI. Doing a TT ZL1 build with Huron Speed. Sent Parish a message hopefully he answers.

[oldman]

Since you are boosted, I don’t think ultimate flow numbers mean all that much. Txspeed look good, titanium intake, you can have them order Manley exhaust inconel and install. I’d go inconel for turbo.

[parish8]

I have been trying to talk to someone at Texas speed and find out if they can put some Inconel valves in their heads. I can’t get anyone to return my email and the wait time is long on the phone. Also I am not 100% confident in whoever it is that might pick up the phone. They seem really busy.

[parish8]

Originally Posted by KingLT1

The CID heads were flowed on a larger bore(4.125) then a stock LT1/4(4.065) and If I had to guess the PRC and Mast were flowed on a stock bore. I also would like to see data for all lift ranges on the CID because the low lift numbers are equally if not more important.

That being said the PRC look really good for the money but I would agree on the Inconel valve for the exhaust. I kind of like the Mast heads with Stainless hollow intake and Inconel exhaust with polished dual spring kit. Shouldn't need any more valve spring then that unless you plan on going solid roller or really aggressive hyd cam.

I think with a turbo set up and 20+psi of intake and maybe as much as 30psi Of exhaust pressure trying to push the valves open the valve springs become pretty important.

[KingLT1]

It is important for sure but that doesn't mean the dual .660 lift springs won't handle that task. It depends on how aggressive the cam is combined with the boost. Your setup might call for a 1209x.

[oldman]

Most of my FI experience was with 4v engines, so I was caught flat footed when the boost and valve spring pressure came up. I have TSP .660 springs and my first cam was a TSP cam, it is my opinion that TSP uses really aggressive ramp profiles. So I would NOT boost on said cam profile with said .660 springs. Or I was just unlucky??

I really think that a custom profile from Cam Motion is the way to go. My .596 lift gentle profile cam seems to have no issues with boost and 7300 RPM now (want to do 0-60 in first gear just for grins, figure I'm losing .4 seconds right on the shift, gotda keep up with King). I'm still on the .660 springs and kit. Had to spend a lot of time with measuring push rods (had not done that in years).

Manley has a pretty good write up on valve bounce and why you need Inconel. That convinced me for sure the stock hollow intake is just a boost disaster waiting to happen.

[Choda]

Are you staying with LT1 heads or upgrading to LT4 style head?

[GTO_Gregory]

Originally Posted by parish8

Having choices in aftermarket castings is kind of new to the lt world. I don’t think there is much known about any of them but maybe some comparisons can be made to the same brand ls counter parts? Also there are some flow charts but not identical conditions so what is that worth?

The cid heads look cool. Here is a set from lme with flow numbers. Something like $5400 all loaded up. Ti and Inconel valves and good springs. https://www.latemodelengines.com/ind...lt4/cid-1.html


Here are some from mast. Pretty much the same price once loaded up. They are not 6 bolts like the cid heads but currently that is of no use. The flow numbers are down but i don’t know the test conditions. https://www.mastmotorsports.com/prod...-cylinder-head

Then the prc heads. They are more like $3000 but you can’t select an inconel exhaust valve. I called on this and the guy on the phone said it wasn’t even an option, that seems odd to me. I will be bouncing off the 2 step at times. I think I need the Inconel. https://www.texas-speed.com/p-9209-p...der-heads.aspx

Thoughts?

----------------------------------------------------------------------------------
You can check out the Kateck LTK heads. They flow LS7 numbers, but the cost is premium at $6,999.99. The intake port is 327cc and it uses a 2.2" intake valve. So, you need a big bore cylinder. They use these heads on their N/A LT1-427 to make 700HP.
https://store.katechengines.com/kate...eads-p854.aspx

Take a look at the Gwatney Performance Ported LT1 heads.
These have 320cc intake ports. They flow big numbers and are priced right at $2,190.00 a pair. You'd have to call them for the intake valve size.
https://gwatneyperformance.com/produ...ylinder-heads/

[Joshinator99]

Originally Posted by parish8

I have been trying to talk to someone at Texas speed and find out if they can put some Inconel valves in their heads. I can’t get anyone to return my email and the wait time is long on the phone. Also I am not 100% confident in whoever it is that might pick up the phone. They seem really busy.

If you haven’t made a decision yet, talk to Tom at Mast. He was able to get me Inconel for my exhaust valves. Seem like good people to deal with so far.