Well I am gettign my stock heads ported, polished, 3 angle, new stem seals, and new valves. Now I am in the process on installing hot cam kit and I was wondering if lt4 valves would fit in lt1 heads. Or if you guess would recommend others larger valves that would be good for an upgrade.

 

Yes, they do. No, it's probably not worth it.

Unless you are machining out the seats you won't find any real gains with larger valves (although maybe some valve float sooner due to their extra weight).

Replacing the stock valves with Manely Pro Flows' or Ferrea's would be a better choice if you're set on new valves.

What flow numbers are you looking for?
Target hp?
new springs? (hopefully not the GMPP LT4 springs that come in the kit)

 

that's odd, I have always read that the LT4 valves were lighter weight dispite their added diameter due to hollow stems?

 

I am using GMPP hot cam springs that came with the kit. As for lt4 valves I also thought they were lighter. And as for horse power, I am looking for as much as I can get and still pass emissions (the pipe test).

 

They are, and in fact are VERY expensive just like the hollow stem Ferrea valves.

One thing that blows my mind is when head porters replace the LT4 stock valves with oversized ones such as a 2.02 valve. That makes no sense to me, why gain 20% in weight to get a .02 bigger valve. They say it's for flow, but some of the best LT4 head numbers I have seen are with a 2.00" valve. In fact the guy that did them said they flowed the same with the 2.00" valve as they did with the 2.02" valve. Now if you were going to a 2.08" valve and the head throat area would take that corresponding size then yes that might be worth while.

For a LT1 head, the LT4 valves would be nice to use if you had them laying around, if not then a 2.00" valve in the stock seats would be the way to go. Other than that put a bigger valve seat in there and get a 2.055" valve.

Bret

 

they are... I wasn't refering to LT4 valves... I ment larger valves in general (which doesn't improve flow rates on stock seats from what people post here).

 

I agree with Bret's (SStrokerAce) post. However, there are circumstances/conditions that require longer valves, or a more durable valve, which would exclude the LT4 valves. Fortunately, this is the exception to the rule.

 

Very true!

Then a Ferrea F1046P (2.08 x +.100 Hollow Stem 11/32) would be a great way to go then! But if you have to ask how much then you can't afford it.

Seriously what Arnie said is dead nuts.

Bret