You will need to measure the actual retainer to seal clearance to verify that you have proper clearance. Using a beehive type spring such as the LS springs with Comp 787 retainers can gain you clearance to just over .500" lift without machine work.
You are aware that the Vortec is a roller lifter/cam motor?

 

I'm aware about the rolller lifters. But I also read that you can use hydraulic lifters that are used in a normal small block if you use longer pushrods.

 

Yes.You can convert to a flat tappet cam, but, it's not a very good, or, smart thing to do for several reasons ranging from longevity to performance.
If you decide tho to go ahead, you will need to measure the retainer to seal clearance to verify.That .466" lift could very well cause a crash between the retainer & guide on some Vortecs. I've seen overall retainer to seal clearance to be as low as .470"on these heads, which would give you .004" safety margin.You want that margin to be closer to .050".
Tell us a little more about your ride, budget,& what you're plans for the motor are & maybe we can help you out a little more.
Unless this motor has really high milage, or, been abused, the roller lifters can often be reused.

 

Most guys here would kill for a roller cam block.
If you're on a budget, get a "take out roller-cam" Scoggin Dickey and Pace Performance used to sell several different ones; they may have one that suits you.

 

I'm just looking to have a reliable motor with a little more performance than stock. I'm throwing it in a 86 k10 that had a 305. I'm on a pretty tight budget and had that cam laying around so I was just curious. But it sounds like I should just stick with the stock cam and lifters.

 

A really good budget friendly choice for you would be the GM Ramjet cam (#14097395). This cam is a great all around roller cam for a truck.It'll put you at approx. 325 HP & approx. 400 ft/lb of torque & that torque will start coming in below 2000 rpm & remain flat out to almost 5000 rpm.
It has .430/.450 lift with 1.5 rocker arms & will work with the stock Vortec springs,although,I would strongly suggest better springs,or,at least new replacements.
These cams sell brand new for about $170,or,you can often find them as new pullouts on Ebay from $125 to $150.Not a lot more than you would spend for a flat tappet cam & new set of lifters.
IMO,you would be better off with the stock roller for now,rather using a flat tappet.Later on maybe a roller will be more achievable for you.
What are the other specs to that cam you have? Duration @ .050? LSA/ICL?

 

I'll definitely look into that. Thanks for the help!

 

Could I use the stock rockers with that cam?

 

Yes,the stock self aligning rockers will work great on that cam.

 

Holy cow, x2 ^nth degree with Joker and Autogear mentioned. Putting a hydro FT cam would be an awful thing to do right now. And I agree with Joker on a used RamJet cam, but maybe holding off on the build until you drum up an extra $100-150 for a well designed cam for your application.

You will be able to blow right past 300HP and could knocking on the door of 400 with the correct cam choice. Whatever you come up with will be night and day as compared to a tired 305. And wow, what an easy swap - it's great to see you stumbled into a 350 Vortec moto - what an improvement.

Remember - just say no to crack (and FT hydro cams) :thumbup:

 

Optional to the 14097395 cam would be the 12551142 cam. The 14097395 is ground on a 111 degree lobe separation angle and is not considered by some to be computer friendly, while the 12551142 is ground on a 115 degree lobe separation angle and may work a little better in a computer-controlled motor. Further, it has an intake duration of 203 degrees @ 0.050" tappet lift and an exhaust duration of 210 degrees @ 0.050" tappet lift, so it is a little hotter cam than the 14097395. Lift is 0.446" intake and 0.450" exhaust, using 1.5:1 ratio rocker arms. A light ghetto grind of 0.030" to 0.050" on the retainers would re-establish the safety margin between the bottom of the retainers and the tops of the valve guide seals.

 

The 12551142 is a great cam & if you can find a used 1 it would be a good fit.That is the LT4 Production cam(not HOt cam). GM has a very few of these cams in stock listed as NOS,but,they carry a price tag of $341.
The LT1(#12551705) cams,however,are pretty plentiful used & can be bought really cheap.I bought 1 over at 3rdgen,org for $35 shipped.There were a couple of these used in LT1 motors. 205/207 @ .050 with .450/.451 lift & 202/207 @ .050 with .450/.460 lift.While either of these would work well & probably be a cheaper option for you,you will be giving quite a bit of torque across the rpm range compared with the Ramjet cam.That can make quite a difference in a heavy truck with taller tires.The Ramjet cam has an LSA&ICL of 109*.While some think the 109* LSA is hard to tune & not computer friendly,it really is.The duration & overlap is so small that the 109* doesn't really cause that much of an issue.I ran mine with the stock tune in my 97 Vortec for a good while before having the PCM tuned without problems,other than an engine light occasionally.Tuning did wake it up & made the cam specs more noticeable.In a carb'd motor,you should have no problems what so ever tho.