Before I start, I promise I've used the search feature thoroughly. Everyone's path is a little different, so I'm seeking some clarification on mine specifically.

I've got a '90 L98 (90k+ miles) with the stock everything except the following:
"Cut Lid" + K&N Filter
MagnaFlow Catback

I am going to order a FIRST TPI Intake and the associated pieces, but while I'm in there I was considering replacing the stock rockers with the Eckler's Competition Cams Rocker Arm Kit. And while I'm doing that, I figured I might as well change the valve springs out as well. This seems fairly straightforward, but I'm sure it's not. I'm going to do new cam in the future, but I haven't figured all that out yet. I figured the rockers might be a good intermediate step to set me up well for the next set of modifications.

Any words of wisdom or advice going in?

 

I don't know what Ecklers is subbing from CC but 1.6RR in general is a good idea. Remember it is just a SBC Gen 1, so a lot of parts work there. To fit under the valve covers though you will probably have to attack the cover with a dremel.

Unless I saw something with the valve springs, I would probably leave them be until a cam change, when you have to change them anyway.

 

My understanding is this kit is compatible with the stock covers.

Do you think there would there be any complication with changing them now? I was looking at the COMP Cams springs which I think would be compatible with a more aggressive cam down the line,

Thanks for your help!

 

I'm not sure I'd call rockers a "while you're in there" item for an intake manifold. Unless I'm mistaken you don't need to remove the VCs for an intake swap, and I don't think having the intake off would help you get the valve covers off. I've done both (intake and VCs) a good number of times on my 1990. I also don't know how worth it rockers + valve springs would be on their own. Sure, the 1.6 ratio gets you 6% more lift and a touch more duration, but I don't know that will get you anything with stock heads. And yeah, a stiffer valve spring would prepare you for a bigger cam down the road, but you might as well just do the springs when you do the cam.

I'd consider doing the cam when you do the rest of this. You have to pull the intake and rockers to do the cam, so it will be double the work to do intake and rockers now and then cam later. I've never done a cam swap in the car, but it's supposed to be doable. I'll be honest, it sounds like it sucks. I can tell you the alternative (pulling the engine) definitely sucks.

A couple things for doing the rockers and springs. For one, a roller trunnion rocker (where the central pivot has a bearing) is a touch better than a ball-and-stud rocker like you linked. Probably not a big deal, but just FYI. Also, be sure those rockers will fit under your valve covers. It can be very hard to find valve covers that are tall enough to clear rockers but low enough to fit under the passenger side EGR pipe. Lastly, you could end up having to pull the heads if you drop a valve while you're doing springs. I've never done the job, but I think I've read that you can stuff a rag through the spark plug hole with the piston at TDC to catch the valve if it falls.

It's been a long time since I've looked into the cut lid mod, but I don't think it's worth it on a stock engine. I'm running a 383 putting down an admittedly sad 330hp or so, and my manifold pressure does not measurably drop at WOT and redline. If the stock airbox were a restriction, it would be causing a pressure drop in the intake. The fact that there's no pressure drop means nothing ahead of the intake manifold is limiting flow at this power level.

Exhaust is super personal, but just be aware that some people are bothered by drone with Magnaflow or Borla catbacks. I went with Corsa and have been very happy; I am surprised to say that there's still no drone with long tube headers and a completely custom 3" dual exhaust. That said, I sometimes wish it were louder and have been eyeing electric cutouts. I also sometimes wish it were quieter!

I'm interested to see how the FIRST turns out. I had my eye on that for a long time before I got my Superram.

 

I would not bother with those rockers, I would only go for a true roller as suggested above.

 

I'll look into some true rollers then! Thanks again for the advice.

 

Interesting... Eckler's sells a plastic lid that's already opened up with a K&N filter included. It was a cheap modification to get my feet wet. I'm surprised to hear that with a 383 though. The forum is full of "cut lid" threads, but a drop in inlet pressure would be a pretty big tell for inlet restriction. My golden driving gloves could have sworn they felt a difference!

I've never heard it with the stock exhaust, but I will say it's a little droney. Nothing terrible though.

 

Looking at the cost of true roller rockers vs a new camshaft, I'm not sure the rockers make sense ahead of the camshaft.

That being said,,, You guys think I should just opt for the new cam instead? If so, any recommendations? I'd probably opt for springs at that point. Seems like it's an all-round benefit.

I know the LT4 hotcam is popular, but my understanding is you want to change the intake to something closer to an LT1/miniram intake to get the higher revs to match the cam design. I'm sold on the FIRST, so a different intake is out of the question.

 

The cam will definitely give you a bigger benefit, albeit at the cost of more work (in the short term; less in the long term). I don't know a ton about the hot cam, but from the little I know and looking at its specs I think it would do well with the FIRST. If you want a tame idle, I think the LPE 219 would be a really strong bet. Don't be fooled by the relatively small duration on paper; that gives it a tame idle, but it has a very aggressive ramp that gives it good top end power. Some forum members have run in the 10s with it on a Superram with more displacement. I believe bjankuski made 430hp with it on a Superram 355. FIRST revs a bit higher than SR as I understand it, but it should be comparable.

 

Looks like the LPE 219 required 1.6 rockers, so I would need to do both?

EDIT: The datasheet has specs for 1.5 rockers, but the website says it requires 1.6.

 

Data sheets typically always list specs for 1.5 for cams, this is normal.

219 does not have to have 1.6s, you can do 1.5s, but I'd do 1.6s. Certainly do the RR when you do a cam, since you'll basically have the entire top end apart anyway.

 

The datasheet I linked shows specs for 1.5, 1.6, or even 1.7 rockers. It recommends Comp 977-16 springs for 1.5 or 1.6.

You'll save yourself a little work if you do rockers now, but it's not totally necessary. Doing rockers requires pulling and later removing valve covers (30min to an hour; you need to unbolt/remove the alternator, AC compressor, and EGR crossover), removing and replacing the rockers (10min), and setting preload. Setting preload could take an hour or two depending on how efficient you are. So you're looking at a few hours of additional work to do rockers later.

I think Engine Masters did an episode on roller rockers; at these RPMs you're probably only talking about a few horsepower from the roller plus possibly a bit from the small boost to duration and lift. The few hundred bucks it takes to do the rockers might be better put toward headers, porting your intake, new heads, etc.

 

Nothing wrong with the 219 cam suggested, might work well with FIRST. However you will need a custom tune with the cam change, as you'll have dead spots in your band if you don't because you may not have enough fuel somewhere in the RPM range. Will it run? yes. Will it be a dog somewhere? Most likely. It may be that way either way with just the FIRST intake installed on it. Remember an engine is a package, everything must be selected to go together.

The custom dyno tune will run in the $500 range usually, so add that in with your springs and cam choice, along with any other things you replace while you're in there. You can see how the cost explodes.

This is why on the intake side, its just fine to do the 1.6RR first before the cam is changed. The RR change frees up 10-15hp usually, and does not require the chip to be redone. You can adjust fueling as needed with an AFPR without going to the expense of a chip. Likewise the headers or any exhaust changes do not require the chip to be redone.

 

Ahh, I meant to mention the tuning aspect. Even the FIRST manifold is enough of a change that I think a tune would be merited (even if just a street tune). Tuning it yourself is also an option (that's what I did), but that's a whole other discussion.

I think 10-15hp is ambitious for just a rocker upgrade, but I've never seen before/after dyno sheets. I'd be interested to see any real numbers on the subject, even a change in 1/4 ET.

I don't think I'd want to use an AFPR as a band-aid. Pulling numbers out of my butt, let's say FIRST + rockers gives 60hp. That means you'll need around 25% more fuel to keep air fuel ratio the same. The mods won't increase VE at idle, so it will have to pull that 25% back out to keep it at stoich. This would require a BLM of 96 to correct, which is at or below the minimum BLM stock programming allows. If you're okay with your car running rich some/all of the time, that's not a problem, but it depends on your preference.

If you don't want to use an AFPR, you can tune it with a Moates Ostrich for about $200. Without a wideband oxygen sensor you'd be guessing at WOT changes, but it would be the same with the AFPR. And being able to tune has the added bonus of allowing you to get part-throttle back on track. Not to mention you can do stuff like adjust the factory shift light, disable first to fourth, change fan temps, change idle speed, enable/disable DFCO, etc.

And if you're planning on doing a lot of mods, you might even consider a standalone. My Ostrich has served me well for years, but I'm looking forward to the added functionality and ease of use of a Megasquirt. But if we go down that road you'll end up replacing the entire car "while you're at it", so don't let me talk you into scope creep

 

AFPR is only a stop gap til you do a real tune, and is really meant for more fine tuning once a chip/tune is complete. And most folks here would be very hesitant to jump into tuning and potentially screwing something up bad due to lack of knowledge. If OP wants to do his own tuning, that is another learning curve entirely, and I would not recommend it except to folks who have a lot experience modding themselves but it is an option if he wants to buy the Moates stuff as well and learn it. Again, more cost, which he doesn't seem to want to jump into at this time.

Several posts here over the years show 10-15hp gain from 1.6RR upgrades, pretty common in the archives. Typically only shown on LT1 cars but some L98/Gen 1 folks have posted that level of gain.

 

Fair enough, tuning can be daunting. However, he could accomplish the exact same thing as the AFPR by just changing the injector flowrate in the tune. And then whenever he is up to taking on tuning himself he can do it the right way. I guess if he never wants to learn to tune though, the AFPR is his best bet shy of paying someone to tune it.

I'm having trouble finding those posts. I see lots people parroting the 10-15hp number but no dyno sheets (and some dubious claims such as lower oil temps with roller rockers). I see a thirdgen post where someone got about 20hp from roller rockers, headers, and a cat back, but 20hp is a pretty reasonable number for just the exhaust. I have 1.6 rollers myself, so I'd like to think they're worth something. But I'm a numbers guy, and I can't find any hard numbers saying they're worth it on a mostly-stock engine.

Here's a nice summary of the engine masters episode; even on a 500hp engine the roller tip had no gains over a stamped rocker and the 1.6 ratio only gave about 18hp. And that was spinning to 7000rpm.

 

I'll send you a message!

 

The tuning stuff is a great reminder. I know the more I do, the more a tune will become critical.

It's worth noting that I will be adding an AFPR as Ken from FIRST recommends it.
https://firstfuelinjection.com/shop/...gulator-307030

 

I changed exhaust and 1.6 stamped roller rockers on my 1989 full-size GMC Jimmy with a TBI intake. I could feel the difference off-road. MPG surely noticed also.

I would put rockers with the list of cheap mods that help everything add up from insignificant to noticeable.

 

Why does he recommend the AFPR? Just to extend the range of your stock injectors?

Butt dyno results, especially in combination with other mods, are not terribly reliable. I also cannot imagine why increased ratio rockers would improve MPG.