Im doing a little upgrading on my l98.

750 carb
063 vortec heads

and this cam
https://www.summitracing.com/parts/lun-10120102lk

I called the machine shop and they told me i should be ok to run that cam with springs and no machine work needed. but every where i look. it says you have to machine the head for the springs.

 

With a 1.5 rocker it will be very close on exhaust side. Will want to measure retainer to valve guide boss clearance, or to the guide seal. Dont want it touching

Cam is fine duration wise but if you have an L98 roller motor then i would suggest a roller cam but they do have more lift and would require machine work

 

As stated above there is no reason for you to NOT go roller. I would go to a set of alex's springs for when you do the swap. Here is the roller kit https://www.alexsparts.com/valve-spr...rf-hyd-roller/

I would also consider staying TPI and not downgrading to a carb, if you do a 750 is a bit big.

 

only reason i dont want to stay with a roller is because of price. i cant stay with the tpi because most of the wiring is shot and i dont want to mess with tuning it.

 

If you're concerned about price, then pick up a used roller cam for the same price of a new flat tappet cam and lifters AND pushrods.
You can re-use your lifters and pushrods if you stay roller, AND not give up as much performance, AND avoid the dreaded wiped lobes & lifters prevalent with flat tappet rebuilds.
Even buying a brand new roller cam, you'll be money ahead in the long run versus converting to flat tappet.

 

That is a terrible reason to not go roller. Wait an extra week or two and go roller.

You do realize you will have to tune the carb too right? Don't forget the wide band A/F kit and a vac gauge + a rod and jet kit.

 

Roller saves cost of oil additives for flat tappets over the life of the engine. But the heads will need better springs and likely machine work. Its a more expensive build but worth it over time

 

I have heard good things about these springs for roller. No machine work and 550 max lift

https://www.alexsparts.com/valve-spr...rf-hyd-roller/

 

Yup they work well but still should get screw in rocker studs for the increased pressures or atleast pin the stock studs

 

Thank you all for the replys i realise i still have to tune the carb. Ive never needed a wide band before. I just checked the spark plugs.

I did not think i would have to change the pushrods just by switching cam type.

 

There is about a .5" difference IIRC

 

Either way get some fresh springs and check clearance very important.
Nothign worse than putting a cam in start and sounds fine pulls good then starts to lay down or miss at 4-5 and falls on its face then you got broken stuff. Dont right it will act the way you want it to.

Bet a 650 holley would be perfect or damn close right out of the box
get one with the adjustable idle air bleeds. Had an old build many yrs ago just didnt have the snap no matter how I tuned (brand new) 750 DP
Borrowed a known good 650DP and it would just smoke the tires instantly need less carb than we all think.

Do what makes you happy and fits budget just dont shortcut with valvetrain.

 

Per Demon and Edelbrock

Q: Does a bigger carb make more power? What’s thelimit?

Demon Carbs responds: Larger carburetors can make more power on a dynamometer, but this can also result in slower acceleration and lower efficiency of fuel atomization. Generally we find that you’re better off leaning towards a slightly smaller carburetor than a larger one, as it’ll operate more efficiently and provide better acceleration for the vehicle.


Q: How do I choose the right size carburetor for myengine?

Edelbrock responds: A simple formula can assist you with this. Multiply your cubic-inch displacement by the maximum rpm limit and then divide by 3,456 to represent the volumetric efficiency.The result is the amount of cfm the engine requires at the maximum rpm limit.

Example:
350 ci x 6,000 rpm = 2,100,000
2,100,000 / 3,456 = 608cfm
A 600-cfm carb would be sufficient.

 

so what excaklcy do i need to do to get my vortecs ready for a high lift cam? ive read all the articles from chevy and z28 forums. do i need special springs if i cut the heads?

 

You cannot use the stock springs on any healthy cam. There are a variety of ways to get more lift and you need a spring to match that application. Pick a cam to match your engine then build the valve train around it. You don't really need to go much past 500 lift on them. They don't flow any better from 5-600 Even 4-500 is not a huge difference.

 

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You will need better springs for a high lift cam. You can call them special if you wish however whether you cut the heads or not, you will need springs for a high lift cam.
The simplest route does not require the heads to be cut. There are several springs and retainer combinations available in the aftermarket that will increase the clearance between the retainer the valve stem seal. Depending on what you select, lifts up to and possibly more than .550" are possible.
That doesn't excuse you from adding screw in studs. Guide plates are optional.

I have no experience with the Alex spring kits posted earlier however I understand that they do the job as advertised. My experience lies with Comps Beehive spring. PN 26915 or 26918 (with associated retainer). They work on my retro-fit roller small block and on Vortecs handled lifts to .550" with room to spare.

 

That is the springs comp recommended. It eas 800 after i prived everything out.

 

Keeping the factory roller parts, (lifters and retainers) means that you're only swapping the cam and adding the better springs. The pushrod length will have to be addressed no matter what you decide to do as any change in the valve train means that the length may have to be changed. That's valve train geometry 101.
With that in mind I shopped the parts out at just under 600 bucks.




These springs should drop in with no modifications needed. The offset locks are needed to help with the spring installed height.

 

thank you when i called comp they set me up with a kit that was in the 900 range

 

My guess is that the "kit" has more than you need. But that's just a guess.
Do you have their part number? I'd like to see what they suggest.