Heres the specs of my heads and cam. which one is the better route ?

the cam is 223/227.610/.614 112 LSA and the heads are 243's with this done to them:2.02/1.60 valves
Patriot Gold Dbl springs, Ti retainers, locks and locators
custom valve job
mill, cleaning and assembly
flow about 305/220

And I will be running a LS6 intake. I will be keeping the rev limiter at 6,000 I didn't touch the bottom end soo I don't want to go any higher. Anyways the roller tip rockers are the comps and they are the 1.75 ratio. The guy is selling them for $250 he's the one putting all of this on.

 

IMO, just do the trunion upgrade to the stock rockers.

 

There's no need to run roller rockers on stock heads. That's one of the perks to running the stock head - being able to run the stock rockers without having to upgrade to new guides or play with geometry.

 

We have run the Comp trunion upgrade in our road race LS motors without issue. We have twisted these 6800-7000.

 

Is .610/.614 lift calculated using the 1.75 rockers? If so, you'll have .592/.596 using 1.7 rockers. I understand the concern for the 98 block stock rod bolts & limiting them to 6K rpm. However, you're leaving power on the table by doing so. May want to consider bumping it up to 6200-6300. Probably still leaving some peak HP behind, but, will @ least be getting a bit more. We agree with what has been posted, 1.7 rockers are all you need. Am not sure that the minimal difference in under the curve power is worth using the heavier 1.75 rollers.

 

just do the trunions!

 

Whatever happened to building the bottom and the top of an engine? Who wants to spend all that money to keep it at 6k?

 

I'd set the rev limiter to about 6400, you'll be fine.

 

No that's without the 1.75 rockers, I have no clue what they would be with them, but I decided to go with the trunion upgrade. Soo you really think it would be safe to spin it at 6200 occasionally ? if it really is I will have the guy change it, I don't want to leave out too much power.

 

I always thought 6k on a stock bottom end was max to stay safe, but as long as it wont grenade my motor i'd feel comfortable at 6200. plus I don't spin it that high all day long but if I want to have it dyno'd or do a highway run i'd like to spin it that high.

 

I had a small budget to work with or else I would go all out and do a 383. But doing the entire topend should hold me over for a few years.

 

I spun my stock bot end to 6800rpm off & on for 1 1/2yrs with a TSP 231-237 cam, dual Patriots ti retainers etc. I updated engine after that for road racing

 

Ohh I guess 6200 is the stock rev limit. I thought it was 6. I guess I don't have to touch anything after all. 6400 sounds even better but idk.

 

If the cam has that lift using stock 1.7's then 1.75 would be .628/.632. Glad to hear your sticking to the trunion upgrade on the stock 1.7 rockers. If it were mine, I'd go 6300 w/ fuel shut off @ 6400. Rod bolts in 98 blocks are not as strong as in later years. Am thinking 2000 & up, but, may have not been 'till 2002 that GM upgraded the rod bolts. So, when guys say they've spun up to xyz rpm, it's important to ask what year block they have.

He's got a 98 block...before rod bolt upgrade.

 

So had I then!

 

Yeah I'll just stay on the safe side and keep her at 6200. I should have plenty of fun spinning her that high.

 

6200rpm is not high! 6500rpm + is getting there.

 

If you're only spinning to 6200, that cam is a waste. Get a 223/227 on a 110+4 or so. You want something peaking in the 5800-6000 range.

 

I was told by the guy who made this can that I'll make plenty of power at 6k. Is at 6400 still safe though on a 98 bottom end ? I want the most power I can get while staying in the safe zone.

 

Of course it was.


Already answered. Rev to 6300, fuel shut off @ 6400. Don't push it further or risk rod bolt stretching; resulting in a spun bearing.