Vortec Heads Question

[franknitticutlass]

A local is selling a pair of used Vortec heads from a 1999 truck. First of all would they fit my 1960's block? Whats the difference in stock and Vortec heads, why are they popular upgrades? Is there any way if I got the casting numbers from the guy that you guys can confirm that they are indeed Vortec heads?

 

[DRIVEN]

They will fit your block. Vortec heads are considered an upgrade because they have largish valves at 1.50"/1.94" and smallish combustion chambers at 64cc. The smaller chambers will give an increase in compression ratio over a smog-era head. The port designs are actually based on the LT1. The Vortec heads are said to be worth as much as 40hp over the old "double-hump" or "fuelie" heads. That, of course, depends on the rest of the engine combination. The main difference in the Vortec heads vs. traditional style heads is the intake manifold bolt pattern. They require a Vortec specific intake manifold which is a little more expensive than traditional pattern intakes. Another thing to consider is the limitation in stock valve lift. Due to the design of the springs, retainers and guides, valve lift is limited to .440ish in stock form. If you want to run a larger cam than that, machining is required. The common Vortec casting numbers are (last 3 digits) 906 and 062.

 

[87National]

Probably goes without saying, but I assume that the heads were removed from a traditional SBC 350 rather than an LS style 4.8, 5.3, 6.0? These also carried the vortec name but were altogether different than the 1st gen SBC.

Also verify that the heads came off of a 350, the 305 heads were different.

 

[koaea]

Careful. I believe a 1999 is an LQ4 with cast heads. It's a GENIII engine, and I don't believe they would fit the GEN1 engine.

Of course, I could be wrong.

There are also LT1 vortec heads, that I think would fit.

hope this helps

 

[87National]

GM continued to use the 1st gen SBC in vans and 3/4 and 1 ton trucks until around 2002. So it is possible that those heads came from a 350 out of a 99 truck.

 

[DRIVEN]

The 350 Vortec was in production from 1996-2001. The GenIII (4.8/5.3/6.0) started in 1999 in trucks. There was an overlap. There is no such thing as an LT1 Vortec.

 

[Oldsmoletick]

Careful. I believe a 1999 is an LQ4 with cast heads. It's a GENIII engine, and I don't believe they would fit the GEN1 engine.

Of course, I could be wrong.

There are also LT1 vortec heads, that I think would fit.

hope this helps

Gen II engines were made up until 2002, but only in full size vans, the gen II lasted until 2000 in full size trucks (classic body style only). So it could be either one. (87National beat me too this)

 

[jrm81bu]

Careful. I believe a 1999 is an LQ4 with cast heads. It's a GENIII engine, and I don't believe they would fit the GEN1 engine.

Of course, I could be wrong.

There are also LT1 vortec heads, that I think would fit.

hope this helps

Gen II engines were made up until 2002, but only in full size vans, the gen II lasted until 2000 in full size trucks (classic body style only). So it could be either one. (87National beat me too this)

Gen II engines are LT1's(and the 4.3 v8, L99?, reverse cooling, opti-spark) only made from 92-97. The Vortec engine was from 96' til 01'-02', these are still Gen I engines. And ya be careful of the 4.8, 5.3, and 6.0 engines as they are labeled Vortec also.