I have come across some aluminum vortec heads from a 5.3L '02-'04 silverado. I have a 350 tpi and I know about the intake bolt pattern pattern.

Question

#1. Will these years of heads fit?
#2. Are they better than iron vortec's 906's and 062's?
#3. What casting #'s should I look for on aluminum vortec heads from that year?

I also came across a new set of cam, lifters, valve springs set. It was for a '96 LT1. Jegs Part for cam is 270-104227. Lift .479"/.518", Duration 272/286, RPM range 1500-5700.

Question

#1. Will cam work in my motor with vortec heads?
#2. Will springs from LT1 work with vortec heads?

 

The heads you mention will NOT fit your engine. Those heads are similar to LS1 style heads.

The cam will fit into your engine. I don't know if it will work well or not.

Don't know about the springs.

jms

 

What are the years I can look for the Vortec Iron and aluminum heads? I still need answer for the LT1 valve sprinngs.

 

Only aluminums are the aftermarket GM pieces. Irons, look for 96-00 years, 062 or 906 castings.

Yes you can use the springs, however, on factory production heads, machine work is needed for valve guide-retainer clearance. Best off probably getting the aftermarket castings. Pro Topline makes iron ones, GM makes some decent aluminums. However, after that is all said and paid fore, add in the cost of the $400 baseplate, and a decent set of non-vortec aftermarkets could be had at probably equal the cost.

 

The thing is that I can get those vortec's 906 or 062 casting real cheap. Like $100 because my wifes uncle works at a junk yard, so that is why I'm going this route. Sorry for this question, but can you tell me a little more about the valve guide-retainer clearance? What exactly needs to be done?

 

The guide bosses need to be milled down otherwise the bottom of the retainer will make contact with the top of it, thus preventing the valve from opening any further. .480" is the generally accepted limit, however, on Vortec's, it's a little less than that because they are factory positive-type valve seals. That's the gist of it.

 

Sorry for the rookie question again, but lets say I take the heads to a machine shop, what would I ask them to do? Would I just tell them exactly what you said on the prev post?

 

Not without machining.
Manley makes a set of springs & retainers that work up to .510 lift without machining. I think it is #43652 for the springs.

 

Tell them that you are installing a new camshaft that has that amount of lift (calculate your needed lift with whatever rocker ration you will be using, if you plan on running 1.6 rockers...). Tell them that you would like the clearance measured (see what you have first, most shops SHOULD be able to do this) and then the guide bosses cut down as needed. Go for an aftermarket diameter (aftermarket positive valve seals - again, most shops should understand this). Probably best to bring in one of the valve springs as well. They can check the spring seats, etc.

 

Thanks, you have been a big help.

 

i just had a set done. i told them .550 to .560 total lift i needed the guides cut down for, needed the spring pockets opened up for larger springs, guides cut down for .530 size stem seals, had the push in studs removed and drilled and tapped for screw in studs. overall cost just under $200 for the machine work. Buying the heads for $150 and spending another $200 on machine work can't be beat for $350 out the door total cost involved.

 

What about the headers? I have a set of hooker headers on my stock L98 heads. Would they fit the vortec heads?

 

Yes.

 

Also have them widen the pushrod guide holes.

 

That can be done at home quite easily, though.

 

Yes Stekman, your right it can be done at home. I had to do it on my vortec heads after assuming the shop had done the job.

 

how'd you widen the pushrod holes when guideplates are being used?

 

Ok, I have been looking at cyl heads and am looking real hard at the Vortecs (due to price, found some local for ~$150). Is there any difference between the 062 and 906? Or was is some model year split?? or is that the diff in 305-350?? If so which would be better for an L98?

 

xpndble - you just punch through the center of the pushrod slot with a 1/2" drill bit.

however before, I think they were talking about "elongating" the pushrod slot for the 1.6 rockers, and not widening them...

 

that's what i thought i read before

 

I used a 5/16" rat tail file in my drill.

Note to original poster, you need only worry about this elongating/widening stuff if you run 1.6 ratio rocker arms (elongate), or decide to do screw in studs and guide plates (widen). If you don't do either, you obviously don't have to worry about any of that.

In regards to the 062 vs 906's (both being the 350 castings - stick to the 350 castings), rumor mill once spit out that the 906's had hardened exhaust seats that reduced exhaust flow. However, in the same rumor mill, this was taken back saying both were good. I am yet to see any flowbench numbers comparing the two. I have personally used the 906 castings and have had no issues with them.