I need a little help reaching a goal. My goal is to be able to run 11.5s in the summer and possibly 11.2s in good air. My current setup consists of 5 year old ARE heads that flow, supposedly, 270/197 @ 600. GM846 cam, SLP shorties, 3200 stall and a 12 bolt. My car ran a best of 11.71 at a raceweight around 3700 lbs.

I believe in having a "streetcar" so I really don't want to remove any of the creature comforts. I think I would need at least another 50 rwhp to achieve my goals.

It's time for a rebuild and I'm weighing my options. It appears that heads have advanced quite a bit over the past few years so I'm looking to upgrade the top end. Streetability is a concern so cam selection will be very important. Now, what about the bottom end. Would I net more power per dollar with a 383 or would a 355 suffice?

I'm looking at both Lloyd Elliot and AI since they seem to be the the most talked about lt1 experts on here.
Can some of you guys please share some of your knowledge and opinions on either your packages or what you think would be the best route to go.

Thanks

 

use the same heads you have now, build a stroker using a SR cam. i'm not quite convinced head porting has advanced any more then what it was 5 or even 10 years ago on a cylinder head design that has been around for decades. i think it's more of either purchasing larger volume/port heads and/or who and who doesn't know what they're doing w/ a grinder.
In the early '90's, Chris Marsh from DFW was in the low 11's while he was Craig Gallant's (GTP) guinea pig before his rise to fame using his heads, 306 cam w/ stock displ.

 

Honestly, you are making enough power to run 11.40's now. Just work on the launch - that's where you are losing all of your et. If you are pretty set on a rebuild, I would strongly suggest building a 383. They make similar hp to the 355 but you have 40 ft.lbs. of muscle to go along with it. You say you want to run full raceweight so that's the direction I would go. If you just pulled those heads off now and got a new valve job and bumped up the compression using the Mr. Gasket .026 head gasket, you would be in business along with some suspension work. A few hundred more stall rpm wouldn't hurt either.

 

A 50 shot of nitrous would get you where you want to be pretty easily.

 

Looks to me like you have a good setup now with the small cam. Have you thought about getting longtube headers instead of the shorties? Also has your intake been ported? Those 2 things may get you to your goal. If you need to rebuild anyways I would go stroker because as said above you gain in the torque and with a full weight car thats what you need to get it moving. You can also run a larger cam with the stroker and still retain great driveability.

 

Good points.

 

I really didn't think that longtubes would present that much of a gain over the 1.75" primaries the SLP's have.

As for the power I'm currently making (339 rwhp on a mustang dyno), I still think it would take an additional 50 or so rwhp to get me where I want to be. I don't think a header change would net very much but it sure couldn't hurt...

My heads were rebuilt when the motor imploded a couple years back so I'm not too sure how well they were rebuilt. I really don't want to invest any more money in them if there are far greater options out there. I'd rather start off with a new h/c package and hopefully a few additional cubes.

The intake was ported to match the heads.

 

You don't think the heads you have now will accomodate 50 more rwhp?

 

I don't really know. I'm really not too sure how much head it would take to supply a decent 383.

 

with a 1.59 60' i assume you have gears in that 12 bolt?

 

3.73s. The car has pulled off a few 1.55s.

 

do you want a 11.5 car at just the track, or on the street too? (minus a tire change)...because you can probably get there now with no more power adding mods

 

I want the car to run 11.5s in the summer. Currently it runs 12.0s. I'm not too concerned what it does on the street, I don't street race...anymore , and traction is nonexistent anyways.

 

There is no way that car runs 12.0 with 1.55 - 1.57 60 ft. times at 117. NO WAY! Are those 60's all natural? Can you really cut those times all natural with the 3200 converter and 3.73's? Something isn't adding up. When I ran 11.70's cam only, 60's were 1.52 and 1/8th mile was 7.39. Where are you at? 117 mph is 11.3 - 11.4 territory with a good 1.5 60.

 

I do agree Chris b/c my car ran 11.40's@117mph and 1.5 60's awhile back but I think his car only ran 117mph a couple times, normally 113-114mph. You could run quite a bit quicker with your current enigne just a heads/cam swap and little more converter. If you have the cash to do a stroker too then the torque will only help. Later Clint