new mods. good combo?

[66StangGuy]

current setup as follows. everything is stock type except
289 originally
holley 600cfm 4160 vac sec carb.
edelbrock performer intake
302 heads
Hooker super comp. headers 3"
2 chamber flows
strong c4 trans with z gate shifter
3.55 gears (no posi yet)


new mods.
elelbrock victor jr. heads. cast iron
roller rockers
comp cams 268H dual energy camshaft
new lifters, springs, retainers...

rejetting carb and using new dist. advance springs to find best curve.


what power increases do you think i will gain. anyone have this setup? street car daily driver.
60cc chambers and 268h cam will i have really low compression?

anyone have this setup?
anyone have any questions comments. trying to decide to order these parts or not. What do you guys think.

also these heads have same bolt locations right? so i dont have to use a special intake or header on it. also after the cam and head swap what intake should i look at next?

[Frankenstang65]

It looks like a pretty good set-up to me. From what I've heard, the victor jr's are great heads, definitley have a lot of potential when mixed with a other strong components.

Actually, your set up is pretty similar to mine...I'm currently running the 268H in mine as well (and i know this is what rev runs too...and he pulled a 13.3 in his car).

I just got my engine back together not too long ago, so I haven't made it out to the track, but can tell you it definitley pulls hard (I can gently bring the car up to 2600 rpm in low, and then just by clicking the shifter up a gear will cause the car break loose for 8-10 feet on completely dry pavement...lol) . In some ways, I wish I had gone with a little more agressive cam, but overall I'm really happy. It seems to fit the stock converter and 3.55s really well.

Make sure you check piston to valve clearence for sure. Adding the extra lift and duration with the 268H plus the fact that you have much bigger valves could make things a little close on a stock short block. Since I have the 1.7 rockers, I have a little more lift then you will, but then again, my pistons were dished slightly and had small valve reliefs. I don't think you'll have a problem, but check to be sure.

I wouldn't worry too much about the compression thing. Yes, you compression will be slightly lower (i think stock was like 53 or 54cc) but the gains from the better flowing heads and cam will more than make up for that little bit of power loss. You can bump the timing up a bit to make up for that also.

As far as the intake is concerned, I think the performer is pretty well suited to run with your cam. With the duration of the 268H, you won't be making power much above 5500 anyways, and the dual plane design makes better use of the off idle-low end power that the cam is really good for. If you run a single plane (the RPM or torker), it will breathe better up top for sure, but I think you'll lose some in the low-mid range-- and thats where this cam really starts to shine.

[66StangGuy]

wow sounds great. its kinda funny. our cars are almost a mirror immage. mine is a similar color too. also have 3.55's and almost stock converter. one last question for you. carb and timing. what carb do you have and what jets do you run? also did you change the timing springs or do you use the stock ones?? thanks.

[Dark Knight]

do a little port matching on the intake will help with a little more top end.. just open it up to the vic jr heads and blend it back for an inch or so...

I'm running a performer on my 84 with AFR 165's , 600 holley and a stock cam.. power was peaking at 6000 rpm...

[rbohm]

Originally posted by Dark Knight
do a little port matching on the intake will help with a little more top end.. just open it up to the vic jr heads and blend it back for an inch or so...

unless you are going racing that is a bad idea. for the street you will get more throttle response with a slight mismatch, and the intake ports being smaller. it all has to do with the pressure waves that develope in a running engine. the port mismatch reflects most of that wave back at the intake valve and actually helps cylinder filling.

[Frankenstang65]

one last question for you. carb and timing. what carb do you have and what jets do you run? also did you change the timing springs or do you use the stock ones?? thanks.

The carb I'm running right now is a 650cfm Holley Double-Pumper (summit # HLY-0-4777C). It's a manual choke carb with mechanical secondaries, and I'm running the 50cc accelerator pumps on it. I wrote down the jet sizes when I changed all the gaskets, but now I can't find the paper. I'm going to pull the carb in the next 2 or 3 days to change the jets (running pretty lean since I did the heads/cam swap). I'll let you know what I was running, and I what I find out works best after I tinker with it some more.

As far as the timing is concerned, I'm using the stock advance springs that came with the unilite. A friend of mine changed out the springs on his ('66 w/ a built 302) and had really good results. I may play around and change them to see what happens, but the stock mallory ones seem to work well for me (and for the majority of people I talk to).

I'm running a performer on my 84 with AFR 165's , 600 holley and a stock cam.. power was peaking at 6000 rpm...

Wow, it's good to know that the performer can still hold it's own all the way up to 6000, especially with your stock cam. I've heard that from a few other people as well. I've yet to run my car on a dyno (I care more about track times than HP numbers....) but I plugged all the specs into desktop dyno and it says that will a dual plane and the 268H I should see peak hosepower power at around 5600 and peak torque near 5300.

As long as it runs a good ways into the 13's I'll be happy...lol. *fingers crossed*