I've had my rebuilt motor in for a week and I think I'm going to be pretty happy with it! smile.gif Been taking it on some short runs out here in the country and adjusting at the carb and timing. I don't know how else to explain it but the whole car just feels LIGHTER. I'm assuming it is because I picked up some torque and HP. I went from stock 70' 402 (350 hp) to:

bored .30
Performer RPM intake
Holley 750 (3310-2) vacuum secondaries)
Ultradyne 280/288 cam
1.75" primary BlackJack headers
Flowmaster Scavenger (4-2-1) Collectors
H-pipe
Dynomax Ultraflow Mufflers
2.75" tails
Machinist tells me he kept my compression at 10.25

Wonder what kind of HP gain I've got?

Switching from the quadrajet to the Holley I can no longer feel the secondaries kicking in. How can I tell if they are working?

Other issue I've got is I'm wondering if my ignition is not up to snuff as it seems to start breaking up or "sputtering at 4500 rpm's. Still running stock points ignition. Any thoughts?

Sure am excited to get it back on the road! graemlins/thumbsup.gif :D

Scott,glad to hear you're having some fun graemlins/thumbsup.gif
The sputtering you mention reminds me of having too stiff a secondary spring and the secondaries not opening at 4500..what one do you have? Anyone one of the yellow springs works the best IMHO and experience.

scott sounds like a fine upgrade on a stock 402, I'M doing the same set-up , a 402 , .30 over , oval ports with 2.19 intakes and the oerformer intake with the holley 750 and a comp cams bump stick 292 , only my motor is on the stand , fresh and dying to get dropped in , waiting on a power steering box change over before dropping it in. hope you find your gremlin - mark tongue.gif

Chris,
I have the spring kit at home and can't remember off hand which one I used. I will look through the kit tonight and figure out which one is missing! How fast can I safely spin this motor before entering the danger(red)zone? Stock motor red-lined at 5500 rpm's I think. I know it was in the yellow at 5200.

Mark,
Thanks for the good luck on chasing that gremlin! Hope your engine gets in there soon so you can be smiling as much as I have been lately!

:D :D :D :D :D

Scott,6000 rpms shouldn't be a problem after you get some miles on it.

Scott,
If you decide to change the springs in the vacuum unit, below is a link to the various springs and their RPM they open at. I have a 454 with a Holley 750 Vacuum secondary square flange carb on my Chevelle with a 3.31 rear axle, 4 speed trans. and I am using the lightest yellow spring with good results.

Sam
Holley Spring Rates (http://www.holley.com/HiOctn/ProdLine/Products/FMS/FMSCA/20-13.html)

Do you know which spring the Holley 750 comes with out of the box?
Ron

Originally posted by ToocoolZ28:
Do you know which spring the Holley 750 comes with out of the box?
Ron I think its the black or natural spring

All of that extra power you are feeling is from those ported header gaskets we discussed a few weeks ago :D

Chris,
I used the natural(no paint) spring in mine as that's what was marked "standard" on the kit. Didn't know where to start at so just threw that one in. I've got the whole kit and it says to start heavy and change to lighter springs as you go until you feel a stumble. You are then supposed to go back to the previous spring. I think I'll skip the purple and try the short yellow(lightest) since Sam is having luck with it.

Sam,
Thanks for the link. I've got the same rear gears and a 4-speed but you've got some cubic inch there!

Jim,
lol! Every little bit helps right!? No problems at all with those gaskets leaking so thanks again for the suggestion, they're a winner!! Even after several heating and cooling cycles, I tried to retighten the header bolts and couldn't budge them! No leaks! graemlins/thumbsup.gif

Scott,with the standard spring,your secondaries aren't even opening.I have very good luck with either one of the yellow springs.