Headers are fab shop 2 1/8 to 2 1/4 with a 4 inch collector

No clue what the heads flow. Just bought them from indy and had them milled to 62cc and cnc'd . I know they need more work but i always like running them the first then over the winter work on them and see what difference is made.

Al you were running B-1 heads correct?

We have run B1, Indy -1 345CNC and OOTB -1 heads on the car. The cam in the 345 head and b1 heads were similar. The 345 head went 4.80's here in Vegas in GOOD air for here.

FWIW we run a MUCH smaller header as well. I know you know this but in a dragster with a glide the converter is gonna make or break the deal. We try to get to 6-700rpm drop on the shift. We have been 1.02 60' here in Vegas as well on a little bubba.

The entire car is apart now and we are redoing it from end to end. Also building a new engine, hoping we can go .50's here, not sure we will get there but that's the goal.

Well I'm sure you could pick up some power with a different cam but if you are using shaft rockers there is a limit to how big you can go before you'll have problems. Do you know what valve springs are in the heads and what the installed height is? If the heads came from Indy fully assembled then the parts might not be in the best shape. Indy sends stuff out the door assembled for shipping rather than assembled for racing.

Do you know what your valve to piston is with the existing cam? If you know that number and the installed height on the springs then you could get really close with the next cam choice.

Personally I don't think you need to change the cam much. Maybe put the 1.60 rockers on there and double check valve to piston and spring clearance. If the 1.60 rocker fit and work then try it at the track and see what it does. Since you already have the parts that will give you another clue.

K motion k950 springs installed at 1.950 i do believe.
The rule of thumb is .060 between coils correct to prevent coil bind.

I do have a ton of valve to piston clearance since the pockets in the pistons are a little deep.

K-950 springs bind at 1.150 so you can't run much more lift than what you have right now. You could probably run the 1.60 rockers but it is going to be close, especially on the exhaust. Maybe put a pair of the 1.60 rockers on and check them. With lash and rocker deflection you'll probably be okay but I don't think you can put a bigger lobe in there without changing springs.

I don't know what those lobes are that you have so I don't know if the K-950 will control the valve train at 7000 rpm with the 1.60 rockers. If you aren't having any problems now then maybe they can handle the extra beating that the 1.60 rockers will dish out but you'll want to keep an eye on it.

If it was me I'd put the 1.60 rockers on there and check it over carefully. If it looks like everything clears then I'd run it down the track a few times and see what data logger says. If it makes more power then that tells you the direction to go, if it doesn't then that tells you something too.

To step up to some faster lobes(I wouldn’t bother changing the cam otherwise), you’ll want to do something different with the spring pack.

My Valiant picked up pretty good going to 1.6 intakes and still using 1.5 on exhaust

I like the idea of using the 1.6 rockers, at least on the intakes. I think those carbs are way too small. This is what I'm using on my new 605 build.

WAY too big there buddy............

They may be too big for your little girlie street lowdeck. Perfect for a grown up engine.

Put shear plates under the carbs. Put a 1/2" spacer on the whole plenum, if it's the newer-style T/R you could make the spacer .75" thick. Use your 1.6 rockers on the intake side of current cam.

I'm assuming it is a single shaft system? I just went thru some old notes on a TD system with a 1.6 ratio (1.52 pivot). Measuring a .4765" lobe with .020 lash on a 760lb spring open load my NET lift was .735" FWIW
I'd guess your current NET is near .670" with the 1.5 rocker.

Good info.....

The 345cc Indy -1's can utilize much more than .700" lift. The exhaust side seems good. I like the duration where it is.

Ask around about those K motion springs. I had k1000h springs and broke a number of them in succsession . i am not sure about the 950s, but guess you might need more spring. I picked up a bunch just going to a comp 947, which had another 90 lb of seat pressure.

Just dug out the cam card and the spring requirements say closed 210lbs at 1.938 and open 650lbs at 1.278.

I checked last night at my k-motion springs are installed at 2.00 inches which is 245 on the seat and they are near 700 at 1.300.

Yes it is a single shaft system and with the 1.5s the cam lift checked 672 intake and 688 exhaust checking it cold of course with the lash.

I am going to stick the 1.6s on the intake side to try that out first.

Not gonna get to try it this weekend as my son and daughter in law are having a reveal party for our first grandbaby! And i darn sure ain't missing that over a dang ole race car!

In my case the k1000h were 225 on the seat, and the cam card called for that much, yet the car responded with almost a tenth gain in ET in the 1/8th! There is a whole lot more to picking the right spring than installed seat pressure, open presure, and coilbind. Spring frequency is VERY important, along with total mass. I am no expert for sure, but just want this information available to you so you can research it, and get the most out of your motor. Dwayne Porter is one of the guys to talk to. He has dynoed a lot of motors, and has a lot of experiance in this area

As I’m sure Greg can attest......... you can spend a lot of $$$ when you’re where you are to find a tenth or two.

My biggest gripe with the k-950’s is they don’t seem to hold up very well when the valve action starts getting quicker.
There are also plenty of people who have had surge problems and breakage issues using those springs, so I generally just use something else.

As for the cam, I don’t really like all that seat timing for the .050 duration and lobe lift.
I don’t think it would be too hard to improve on that cam......but just how much it would improve is the question mark.

All said, I ran your performance #'s and considering such a small cam and assuming you don't have trick ring packs and vacuum pumps and great valve jobs...YOUR MOTOR IS MAKING DECENT POWER now for the compromises. I'd guess you'll need about 50hp? or so for your stated goal? ...I don't see just a rocker change giving you that much but if you did both (well 3) things I suggested it should get you there assuming you don't have a plenum spacer and shear plates. Also as stated your maintenance interval will go up...lifter rebuilds? spring change intervals? with cam intensity. Maybe look at a PAC 1225 spring on the intakes.