http://paceperformance.com/index.asp...&ProdID=178072

Hey guys,

It's time for me to upgrade my 1990 L98. I was told changing the
rocker arms to 1.6 ratio would be just the thing. I researched the forum and found no advice on the need or type for my motor.
I know several of you have done this. Would I need to change the springs out in order for the lift to work? The address on top of this
message takes you to a set of 1.6 self-aligning roller rockers for a great
price.

I also feel it's time to replace the fuel injectors. I found some for
a Mustang that are a Bosch design with a flow of 22.5#. Will these work? I know stock is 22# but I'm unsure of the fuel pressures that
makes these produce the advertised injector pressure.

Thanks in advance

 

If you are going to go through the trouble, get full roller rockers and not just roller tipped ones. I also don't think this is an area I'd want to go "cheap" in. Valvetrain control is pretty important! Look into Crane Gold, Comp Cams Pro Magnum, I think even Summit Racing makes some decent aluminum ones if you are on a budget.

 

There is nothing wrong with the stock rockers, they have worked for decades and hundreds of thousands of miles on tens of thousands of 'vettes. So just the roller tip is an upgrade. If you can spare the cash, go full roller. If I were going to spin more RPM then stock I would look at other options then the roller tip. Yes you will want to replace the springs and valve seals to is a good idea. There have been many topics on this, I am surprised search failed for you.

 

Jegs has a house brand for your car that are full roller and aluminum. I would also go with at least the GMPP 101# LT4 springs when you do the job. Also check your valve seals.
You need narrow SA for the 113 heads.

 

will the stock valve covers handle the 6:1 ratio? and push rods?

 

http://store.summitracing.com/partde...6&autoview=sku

 

They will fit the stock covers with a little bit of work. You just need to grind down the drip tabs on the inside of the stock covers.

 

The narrow body rockers fit with no mods to the V/C but they are like $240! I do not know if the roller tip rockers in your first link need the V/C mods, they look like the stamped steel stock rockers so I would think not. There is no V/C issue with pushrods.

 

Thanks for all the input. What I interpret is if I am willing to shave/grind the inside of the VC a bit I can save money. The
rocker arms I listed at the top may not work well. I'm unsure
why full rockers, if the L98 cannot rev high, are better than the roller
rocker type. These are self aligning and I hope will do the job but
I am listening and appreciate your comments as well.

I didn't get any feedback from the fuel injectors. Any comments?

 

They are Ford injectors? The may flow more then stock. There have been many threads on those. Some found that they flowed to much and their car ran rich. Would you install an adjustable fuel pressure regulator to? The car may need it or a custom tune with different size injectors. There was a thread just the other day about getting stock size injectors.

Here is one:

http://forums.corvetteforum.com/show....php?t=1701576

It looks like there are currently three threads right at the top about injectors.

 

 

The roller tip rockers that you have looked at should be fine. At $80 they are 1/3rd the price of full roller rockers. The increase in effective lift ratio will gain you a bit of HP, but not the 30hp suggested by the web site. While full roller rockers are the better way to go, in an L-98 where you aren't racing it, a stock rocker 1.6 replacement from a quality manufacturer, gives you the best bang for the buck. The roller tip doesn't add anything, (but it doesn't hurt either). If you are replacing the stock rockers with 1.6 units, you should definately replace the springs and valve seals at the same time. Your original springs are probably tired and need replacing anyway. Depending on the rockers you finally decide to use you'll want to ask around for replacement spring suggestions. You will want to double check them at install to ensure that there is proper clearance and no coil bind with the 1.6 rockers.

Ford Motorsport (FM) uses a pressure of 39psi when rating their injectors. GM uses 43psi or roughly 10% more pressure. An FM injector rated at 22.5# will flow more than 22.5# of fuel at 43psi, so you want an FM injector rated about 10% less than 22# to match the GM injectors at 43 psi. I believe that most guys replacing stock GM 22# units with FM units are using the 19# FM injectors.

 

Unless you just like to tinker, or you are having trouble, those RR's aren't worth the effort IMO. Your stock injectors are Multecs like mine, if they are working leave them alone until they break or test bad. If they ohm out O. K. why change?