[fast times]

Hello newbie onboard, I'll make this short I have a ls6 454 in my 55 chevy xe 284 hydraulic cam , single plane intake, 750 dominator carb, 373 gears out back , 325/50 drag radials, 400 turbo 4k stall convertor. (cam is about 240-246 duration, 575-580 lift). My best times are 11.99 at 112 the car is 3850lbs with driver, what do you guys think should I buy some oval port heads like all the mags say now or a big roller cam, if heads then who's do you like or well done 049's?. Thanks

[Super Streeter]

I would stay with the stock rectangular heads.with 5000 stall you wont wee much of a differance going to ovals.What type of intake do you have.If I were running that combo I would run a port matched strip dominator or old style torker along with a 2" spacer and a 4150 type carb.With that engine you need at least 1 7/8" headers and 3.5" muflers for the engine to breath to it's potential.
Another issue is that the LS6 had marginal compresion at best,and real world numbers were about 10:1 with the stock crate motor gasket,or about 9.75:1 with some of the newer thick gaskets.I would run the intake combo and headers I mentioned.If you wanted to dig into the engine you might want to pop the heads off,and give them a bowl blend job as well as have a good 3 angle valve job done on them.If they are bone stock you are leaving some power on the table there.Your car is a tad heavy,and the th400 is heavy too.I would say that you might get a well prepped LS6 to run mid 11's in a car that heavy,but that is about it.If you really want to step it up,try getting the compression up to about 11.5:1,and running a little more cam.I say maybe something with at least 260 degrees at .050,and spin that bigblock to about 6500.That could be a 10 second combo if you do it right.Let us know more about what you have.

[fast times]

Thanks for the reply super streeter, I have had the heads flowed but I dont have the numbers (rookie mistake) , the intake is a weiand team g single plane which is not ported the heads, if that is worth anything I'm not sure. The compression in the cylinders has been checked and it ranges from a low of 185 to 200 psi , so I think I'm close to not being able to run pump gas, although in the great white north we get 94 octane ,at a buck a litre. 11.5 to one comp probably will take me out of pump gas which I would like to stay with. I'm wondering about the difference in a solid cam as opposed to a solid-roller cam, big diff in price, what about performance? In the tens would be awesome, keeping my heads would really save me some cash too. The chassis is pretty good with a 12 bolt 3.73's ladder/bar coil over, mini tubbed 28/12.5 bfg drag radials, the front has 6 cyl springs and 90/10 shocks, weld pro stars all around, the 400 turbo is reverse manual valve body, with a neil chance 10" convertor, (4000-4500), cage with full interior, the headers are 1.75 *3.00 hedmans leading to 3inch flowmasters tailpipes are 3.5inch s/s out to back bumper, (I'll get some pic's attached if your interested) Also roller rockers and a stud girdle on the valvetrain.

[bigbad66chevelle]

a little nitrous never hurt nobody and even better with all those strong big block parts.........

[fast times]

I'm with ya big bad chevelle , but I would like to sort this combo out to its max, before I juice it. If I could run low /mid 11's with the 3.73's and a 28" tall tire I would have some rpm's left for 150hp of nitrous, for sure in the tens then and still drive on the highway at about 2800-3000 rpm. Just love to hear from someone with ls6-ls7 heads and a heavy car, find out the potential of the combo.

[fast times]

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