Okay, I can now drive the 350 fine, so its time for more power. I was reading in Hi-Po Chevy about the soft rock mouse, and I already have the 262 cam, and was planning on a new intake manifold anyway. Can I put Vortec heads on a non roller cammed block from 1971? What modifications would I have to do to the block? I figure that dollar for dollar, Vortecs are the cheapest way to gain power, and would help me gain more power from my other mods. I currently have 1.94/1.50 75cc? 487 heads. I want to go from my current 8.5:1 compression to around 9.2. Thanks.

 

Yes.

None.

You will need self-aligning rocker arms; I'd recommend the Comp steel roller-tip ones in a 1.5 ratio.

 

Scoggindickey has a vortec "package" that includes everything for the swap. www.scoggindickey.com

 

The kit is a little too pricey for my liking and the parts are a little bad quality. Parts store will sell you all the bolts and gaskets, and you wont have to mess around with shipping.

 

your looking at about a 1.2 increase in compression going from a 76 cc chamber to the vortecs 64 cc. You have to figure compression accurately, and try to stay under 10-1. If your pistons are stock dished(not flat-top with 4 reliefs) this shouldnt be a prob, but if they are flat, and you have decked the block etc, you will get over 10.25. You could run this high, but you gotta keep an eye on the tuneup, or just mix a little race gas in with your unleaded, or find someone who sells 100 octane unleaded.
BTW, the vortec heads are very good running pieces, and would really wake up your 350, esp with that little cam, it would be a tire melter at low rpm.

 

As far as it being pricey well that's a matter of opinion . I kind of think it's on the inexpensive side.

 

I have 10.9 compression on my 350 and vortecs. Pump gas is no problem. This is the second year I've had this setup and no spark knock problems yet. My timing is 12 initial and 36 at 3000 rpm. I have always heard of having to stay with really low compression on a street motor but I have a friend that had 11.25 compression and used pump gas for 6 years. It does depend on the cam that you use and whether or not you can keep it cool.

 

I definetly think Im gonna go with Vortec's. Seems to be the best gain for the price. Only problem is do i rebuild the tranny first, as its only a matter of time at this point before she dies. No tranny, no go. Should start saving up for them now. Im gonna wait for when I do this, as I need to pass emmisions I beleive one more time, and I cant find an emmisions legal manifold for Vortecs.
I just want to get Vortecs with 2.02/1.60's and stiffer springs, not 1.94/1.50's with the POS stock springs. And as for a small cam, geez, its the biggest I can run with a computer. Decent power, lopey idle, and best of all, no computer codes!

 

As for the 2.02 1.60 valves in the vortecs don't waste your money on doing that. Many flow tests have shown minimal gains by putting bigger valves in these heads. They don't respond to port jobs and big valves like other heads do for some reason. Not sure why but in the Goodwrench quest 350 buildup in Chevy High Performance they pocket ported them just enough to clean up the rough spots and put a 5 angle valve job on the stock valves. They also back cut the valve 30 degrees. Which helps low lift flow. These heads done like this outflow a lot of aftermarket heads up to .500 lift. I had this done to mine at the machine shop and WOW! what a difference it made. As for springs I got the springs that comp cams sells with the cam kit. I had the spring pressure and installed height set as the cam card specified. The difference was tremendous going from 76cc crate motor heads to 64cc vortecs. I'm sure the compression jump helped a lot, too. Good Luck!

 

It is true you can run a little more comp. if its done right(decking block to minimize squish area, right cam selection, etc), but it is a little risky. I know the vortec heads have a pretty efficient chamber, and this should help. Fuel injection may also help this problem, as the mixture is alot finer than with carbs. I have built a few pump gas motors for performance, but you should be aware of the rrisk. I wasnt slammin your cam, btw, it will run great in your motor. I built a very similar motor to the combo you describe for a friends old pickup, and with 9.2-1, it is a beast. Believe me, some of the stuff I build has 25 more degrees duration @.050 than advertised duration on the comp 262. I guess small was just a relative term. I also agree with 94-6speed, don't spend the extra on the 2.02/1.600, unless you plan on opening up the chambers to unshroud the valves. there is very minimal gains with the bigger valves unless reworked. once again, just my .02 worth.

 

So where would you guys recommend I get my hands on these Vortecs, and what a fair price for worked over heads. I figure if Im gonna spend the money, I might as well go all out and not regret it later. Of course, I can re-use the Vortecs later if my 350 decides to take a dump, right?

As of right now, my tranny is shifting a little iffy and I think thats the most important thing to get done. thats my first priority. But Im thinking of doing the Vortecs during next years spring break. I need some sort of project to keep me busy, this year was body work and 350 swap on the car.

I am willing to run high test in this car, as it wouldnt really be a daily driver like it is now. I need to drive the 2.8 more, but I just cannot handle all of its 107 mighty horsepower. That should be my daily driver, but Im having to much fun with the 350. What happens if my compression is too high and it knocks on high test? Having to run race gas would be a royal PITA, could I just get thicker head gaskets for it?

Thanks again. Hopefully I can crack 12's with the Vortec's. For now Im trying to crack 13's on my current heads.

 

JimPace chevy has the vortecs complete for 450 or so. You can also buy bare heads if you are going to change the valves and springs. If you are running flattop pistons with the vortecs, your comp. should be around 9.8- 10 to 1 unless you have had the block decked. even with the block zero decked, you would be around 10.25. With premium gas, and computer controlled, and esp with efi, you should be ok. You dont want it to detonate, as it will break alot of **** if left for to long. Not trying to scare you, just letting you know it can happen. Higher comp is possible with pump gas, but you just gotta be careful. THe vortec heads work GREAT with just a little minor cleanup in the bowl area, and a good valvejob.
Unless your racing, and willing to spend the money to have a full port job done, and have the chambers reworked to unshroud the valves, id leave the stock valves in them. Just change the springs(the stock springs blow) and maybe convert them to screw in studs and bolt em on. Make sure you either get self aligning rockers, or have the heads machined for guideplates. have fun with your car, it outta be a tire burner

 

Grab a copy of Circle Track magazine and look for Wheeler Motorsports' ads. They sell reworked Vortec heads with screw-in studs, better valves and springs, etc. Not much more than stock Vortec heads...~$300 each or so ready to bolt on.