I have a few questions right now. I do not know ecactly what is in my motor, so I do know that it is going to be tough for you guys to make any suggestions, but if you could give me an educated guess, I would much appreciate it. The motor is a 454 .030 over built to either 427/435 (a tad warmer than that) specs, or LS7. About 450-500 horse, guesstamite. It also has peanut port heads. (I talked to the engine builder and he said he was pretty sure it was either graemlins/clonk.gif ) Don't really know if that helps you our not.

Anyway, I have an Edelbrock performer 2-0 intake with a 750 Holley DP Mech Secondaries. The motor runs very good, verry reliable, and runs like a bat out of hell, but I am always looking for that last little bit. If I were to switch to a single plane intake, and possible an 800-850CFM Mech Secondary DP, would I get anything out of it? Which is better, single or dual plane?

This is a street car, but am looking for a good amount of performance. I am looking for ppower from idle to about 5500-6000RPM. Can anyone reccomend an intake for me? Can't go tunnel ram, no clearence under the hood.

ALso, when buying an intake for peanut port heads, what do I buy for, rectangular or oval ports?

To the other end of the car. I am looking at purchasing slicks for this car. What kind of clicks would you guys suggest? Goodyear, Hoosier, M/T? Alsom what tubes are good? I am ordering out of summit, so they have their brand and M/T? They also have fairly cheap rims in their, but how do I know if they would mount and fit to my car. They are 15X8. I also have the stock rims (the black ones with the trim rings) and could mount them on their to save some $$$.

Thanks for sticking with my lack of knowledge and for any advice,
Chris

Chris,stick with your Performer and 750 double pumper..I ran that intake/carb combo for years on my 454,and has netted me my best ET,a 12.99 with consistant 13.20's with traction issues,and this is 2.73 gears and a TH400
You won't find any performance gains going to a single plane.I doubt the 850 would help too.
If you do feel the need to change the intake,get an oval port Performer RPM intake.
For sticky tires,stay with a DOT slick,like a Mickey Thompson ET Street or Hoosier QT Pro
Most of the time,its not modifications that make a car faster,its tuning and getting it dialed in.I suggest you go to the track before you change anything to get a baseline and see what you got.

Pull a valve cover and see what heads you really have,get the numbers.

Originally posted by Rapid Robert:
Pull a valve cover and see what heads you really have,get the numbers. The numbers I found on the head were:
346236
Pass
GM2T
K5 74

I believe they are 75-87 oval port open chamber heads off of a 454 with 120 cc chambers 225/116cc ports.

Are these any good. Did they flow as well as the 70-72 heads? Would I benefit from a head sway to a new aftermarket set? In other words, in regards to the heads, would the $2000 be well spent as far as me noticing the power?

Any help or comments would be appreciated.

Chris
EDIT: I think I have two different heads. I pulled the driver side valve cover this time and found the numbers above, but the last time I pulled off the passenger side valve cover, and I searched my last post and found a different set of numbers. It says they are 113cc chamber 454 peanut ports. I will pull the other cover tommorow, and will let you know. Is it possible to have an engine run extrememly well with two different heads?

Chris

i would believe they are peanut ports

336781.....73-85...oval...OPEN...454, 118cc chamber, 256/114cc ports

346236.....75-87...oval...OPEN...454, 120cc chamber, 225/116cc ports

the 781 large oval port head have considerabally larger intake runner cc...

http://www.nastyz28.com/bbcmenu.html
on this site
it says the 236 are
346236 1975-87 454 Open 113.0cc


imo, a set of 049 or 781 heads would be a nice swap... that might drop your compression though, so maybe a set of 820? bolt on a pair of stock 049 heads, i am sure you will find a huge increase compared to the peanut port heads that you have. also, i would try a smaller cam... the LS7 cam is pretty large... and when matched with peanut port heads to feed a 454.... besides... the 049 heads are only around $100!

i had a torker on my car, and now, a performer rpm. i definately noticed the gain in the lower rpm with a stronger mid/upper range pull too! idle to 6000rpm is what the performer rpm intake will give you

slpin, thanks for the advice. I really am not sure on the cam, as I did not build the motor, but the builder said it was either the LS7 (more likely) or the 427/435 cam. So the peanut port heads are restricting? Say I have the 427 cam. Would I still notice a difference by going to a better set of heads? What if I went aftermarket with them? What could you suggest for that.

As you can see, I really do not know much about motors. I can build em, just cant peice them togother to put together a strong combo.

Thanks,
Chris

Hmmm...427/435 or LS-7 specs with peanut heads??? 435 is 11.0CR and LS-7 is 12.5CR so what pistons are in your engine, I would guess flat-tops. Listen very carefully to the good advice the guys are giving you about your combo or you will be throwing your money away on lower performance than you have now! With Chris on keeping intake/carb combo you have now! With slpin on the 049 heads! Aftermarket heads get very pricey, then you would want to change the intake/carb you have now and spend even more money! You have a good basic combo now so replace those heads and should some good hp! Have you beefed up your rear suspension to handle all that power?! Good luck with your goals and keep asking questions as the guys here on TC will get you fixed up! graemlins/thumbsup.gif

Is it possible to have an engine run extrememly well with two different heads? Just imagine how well it would run with matched heads. From what you said you have 120cc chambers on one side and 113cc chambers on the other? I don't know how it runs so well :confused:

I think I made a mistake when I looked up the numbers graemlins/clonk.gif I also contacted the engine builder and he said they are both the peanut port heads. I decided not to get new heads because the car runs very well, and I am saving for a new truck so I decided against it. Now I think I am just going for a gear swap.

Thanks for all the replies,
Chris

Originally posted by RedSS454:
Now I think I am just going for a gear swap..what gear ratio?

In my quest to go faster I thought about the heads, and didn't want to tear into the motor, because it runs good, hard, and fast, and is fairly fresh. Also, thanks to the advice of you, and the other people who posted, you guys said it may just be a waste of money. That sounded good. Then I thought Nitrous, but I do not know to much about the motor, and again did not want to hurt it. This led me to a gear swap. I do not do much running at the track, and therefor do not need the really high end speed I would lose with the gear swap. That led me to the gears.

I really do not know what is in the car as of now. Its anywhere between 3.55 to 4.10. I was going to pull the diff cover today, but the weather turned and I plan on doing it tommorow. Depending on what ratio I have now (I firmly belive they are 4.10's even though the spin the tire test said about 3.55) I will take one step numerically higher. I think they are 4.10's because at about 55mph, its at about 3100-3300RPM. I do no racing at a track just fooling around to see how fast I can get up to speed on the highway. I was thinking either 4.33's or 4.56's. If my current gearing is lower to 4.10, I may just stick to the 4.10's. I know that eats gas and puts extra wear and tare on the motor and trans, but it interests me, and if it doesn't work out, I could just change it back.

That lead to a few quesitons. I posted them here (http://www.chevelles.com/forum/ultimatebb.php?ubb=get_topic;f=35;t=002202) this morning, but I didn't get any responses.

That was my last thought on going just a little quicker without dumping a 800hp crate motor into the car, and twisting the frame out. (not to mention I do not have the $$$ for that)

I just like the feeling of getting from 0-60 in a short amount of time. Any other suggestions or if anyone can answer the questions in my other post, I would more than appreciate it.
Chris

the spin test is only the truely accurate way... the mph @ rpm is not accurate due to converter slip.... unless you have a manual and have perfect speedometer and tire height to match it...


i still think your motor would only get better with a set of 049 or 781 heads! the performer 2-o intake stops pulling around 5000rpm anyways, and with a rear end like 4.1-4.56, it certainly wouldnt be the wisest choice.... i would keep your 3.55s... pick up a new cam, and top it off with a set of the 049 heads, or closed chambered if you have flat-tops... a performer rpm intake would be nice too... if your car runs well now... imagine how it would feel with a more matching combo! graemlins/thumbsup.gif

Chris,I strongly suggest you pull the cover,and confirm your gear ratio.Don't think that putting steep gear in is the solution to more performance..better or improved seat of the pants doesn't mean the the car is quicker..if you think so,you're setting yourself up for disapointment.
Maybe just "dialing" in what you have,plus finding out what you have will make things easier.As far as your motor goes,if I had to guess,its a stock rebuild with flat tops and mild cam..and you have either 3.31's or 3.55's for gear.If you where a little closer,I'd help you out-no problem.Cruise up to CT?

EDIT: On second thought, I have found a pair of heads in teh paper for $100. I tried looking the casting number up on Mortec. Can any of you tell me if these heads will help me in my power goals? The numbers are: GM 10T-3993820. Are these worth the effort to put on and maybe help the performance?
Thanks in advance,
Chris

3993820....71......oval...OPEN...402, 113cc chamber, 255/114 ports good heads,semi closed chambers, I'd think they would work well with flat tops.

Chris, Definately check the rear end gearing first. A non posi-trac would probably have a 3.31 gear and if it is an original SS 396 or SS 454. If it's a posi-trac it could have anything. The larger open chamber heads will likely run better with their bigger valves if you have enough valve relief in the pistons. Lots of things to check if you decide to change heads. If you do make sure a good engine man checks everything to avoid disaster later. Grease will pour out of the rear end if you pull the cover and it stinks like hell. Good luck with your adventure.