I have a 67 El Camino 3800 lbs with me in it.

Has a 355 with flat-tops
186 heads (2.02/1.60)
Holley 3310 Vac Sec
Performer RPM
HEI with supercoil
flowtech Headers
Lunati part #00010 Hyd Cam (292 dur / 480 lift)
running about 36 deg total advance
running super unleaded

TB 350 with 12' conv 2000-2200 stall

8.2 10 bolt posi with 4:56 gears 28.5 inch tall ET Streets
Open headers
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Time slip from this combo

60 ft ........2.0196
330ft.........5.6947
1/8th e.t......8.7796
1/8th mph....78.95

left the line at about 1900 rpms, shifted at 5500 rps
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Last week I changed the convertor for a 10' 3000 stall and put a Holley 750 DP with 70 jets front and 80 jets rear. Other than that same combo. Here is the new time slip

60ft........1.8475
330ft.......5.4840
1/8th et....8.5946
1/8th mph......78.22

left at about 2400 rpms and shifted at 5500 rpms
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Traction was so-so on both runs (too much water). I feel like the 750 DP wants more jet in the
rear, I noticed my mph did not improve and actually dropped. kinda runs outta steam on the top end. I figure either not enough fuel or not enough cam.
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Question #1 Does the comparison of time slips show a need for maybe more jetting?

Question #2 I don't drive very much on the street, How much more cam can I go and still be somewhat streetable? I do prefer to stay Hyd and am considering a quick cam & lifter swap.

Any advice is greatly appreciated.

I would keep working on the jetting, check the color of your spark plugs should be a nice tan color if jetted correctly. I would bet you need to lean it out a bit, start by dropping down the rear 2 jet sizes at a time until you start to see a change on your time slips, see if it goes up or down in performance, takes a little time but its worth it. I would rather use the 3310 carb on an automatic car. As far as a cam goes that is a fairly large cam for a 355 already, unless you want to up the compression ratio with new pistons too. Maybe try launching the car at a lower rpm will help also, don't want to load up the convertor on the starting line, make it flash higher with a hard launch at lower rpm. Hope this helps!

BRAD

i agree with the lowering of the launch rpm advice. always makes my car 60ft better. jetting is probably not going to net much, but it's worth a try. my 355 combo was very similar to your's. i had the same cam about the same weight, 4.10 gears and about the same convertor as you, same carb and intake. my best was an 8.56@78mph with a 1.76 60ft time. i jetted mine up and down and it ran the best with the stock 750dp jets in it.

I think you need to turn that motor up about another 1200 or 1500rpm.Why are you short shifting? That cam in a 355ci motor won't start to pull hard until almost 4000.If you feel the need to keep your rpm that low put a smaller cam in not a larger one. And you need more converter,something that will stall behind your motor to 3500-4000. Your trying to launch that heavy car at an rpm where your motor is totally gutless. Remember BIG cams mean BIG RPM.You didn't state what your compression ratio was but a big cam also requires a higher compression ratio to run well. To help put this in perspective I have a 3200lb Chevelle with me in it. I have a 454 with a 286 Engle,11:1,performer intake,750DP,4.11 gears with 28" slicks,a 3500rpm stall and a best to date of 11.10@118 with a 1.47 sixty foot,and I haven't started to tune it. And I shift this low rpm torque motor at 5500-5700. Take that car of your's to the track and drive it like you stole it!

ps I am no kind of Guru,just adding my two cent's.

Ok, as far as your mile per hour goes, thats most likely perfectly normal with a somewhat in-efficient 12 inch converter that stalls 3500. Even though its rated stall speed is 3500 rpm, thats torque dependent(among many other things).....could be more or could be less in the end. Also, it will never fully lock up and there will always be some degree of slippage. So, the new converter probably slips more at all rpm than the old converter did. That explains why you have lost mile per hour vs the tighter converter you previously had. I also agree that you should experiment with different shift rpm. Make mods to get the car to hook as best you can(chassis mods) and experiment with different launch rpm. A lot of times launching at a lower rpm will provide for a better short time cause the car hooks easier. However, this is often just a crutch for the suspension, cause if it dead hooked at say 3500, the car would have more torque to use off the line and and at a higher rpm, and it would leave harder(if it wasnt spinning). So, put some effort into the chassis to promote better weight transfer and experiment with more rpm on launch as well.

Anyways, Im not sure how much higher shift points will help. Based on the camshaft choice, it seems as if it would definitely help cause it could do more rpm, but those 186 heads may be the limiting factor. Depending on what has been done to them, if they dont want to move any more air, than you really arent going to do much better by revving a lot further.....but experiment. Also, about that dizzy, are the guts all stock? At least a better module coupled with the better coil will help spark stability at higher rpm...that just ight be necessary if you try to rev further. What rpm does your total timing come in at? I would do some runs with different amounts of total timing. Try a couple degrees more and a couple degrees less and watch what happens to mile per hour. When you get the best mile per hour, keep that total timing setting. Than try different springs to bring the total advance in at different rpm and go with what provides the best 60 foot. You may have already done all this, but since the only thing you mentioned was the coil, I figured it might be a bone stock hei otherwise.

Anyways, you have definitely got enough cam. If you want more mile per hour you need to rev more...thats the only way it will pick up. And if it wont rev, try timing and fuel adjustments and give that hei a good tuneup(component wise)....like I was sayin, at least add a good module in there. Finally, if it just continues to run out of steam, I would bet that its in the cylinder heads themselves and youve already got a huge cam for a 350, so a bigger one yet isnt going to help anything. Cylinder heads and adequate compression will.

the reason a car will sixty better while launching from a lower rpm is due to higher convertor flash than just mashing the brake and gas and stalling it up until the brakes can't hold anymore which uses up your suspension. the only way i'd ever stall that thing past 12-1500rpms is if i had a trans brake. with the 4.56 gears you have i would say 5500rpms is about right for your shift point, it keeps your motor in the torque band better. a 292 .480 cam is not in the least bit a "big" cam, imo. that cam is designed for maximum midrange power, not to rev it to 7000rpms. you try that like someone else suggested and you'll be buying at least a new cam and lifters when you collapse those hydraulic lifters. it definately couldn't hurt to upgrade the ignition although to me it seems like it's working fine.

loose torque converters will tend to lose mph verses a stocker in your car.You try installing collector extensions they outta be good for a tenth or so.

Thanks for the replys, keep em coming.

The CR was close to 10:1 we figured
The HEI is bone stock except for the supercoil
The 186 Heads are virgin, just a 3 angle valve job

I was thinking the cam I currently have was kinda middle of the road for street/strip cams. This car does get driven to the track and around town, but probably less than 1000 miles a year.

As far as the shift point, I feel like 5500 rpm is fairly close, I could not imagine this motor over 6500 rpm.

When I stall to about 2400, my front suspension rises about 5 to 6 inches. I have a video that shows it, but no place to host it.

This motor was built on a tight budget. Paid $150 for block with spun main. Crank is a machine shop cheapo $50 off the shelf, pistons are cheap cast. Paid $100 for the heads and $125 for the 3 angle and magnaflux. I figured I have about $1100 total in the motor. I am in the process of planning 383 build. But due to mmoney issues I will probably run this combo for 2 more years. (been running 3 years now, and doesn't knock or burn oil).

I was really curious if a quick cam swap would really help. Again I didn't think the cam I have is really that large, a buddy of mine has the same cam and its in a daily driver with air conditioning.

Please keep the comments coming

I think you guy's may be right,after reading the post from 71malibu406 and asbill71 I think I may have been to conservative with cam selection,you probably should try going up one step to the 296 that Lunati offers.It sounds like it might work better with your combination. Please keep us posted on your result's.

From what I can see, you have a 5500rpm head and a 6500rpm cam.

From what I can see, you have a 5500rpm head and a 6500rpm cam. i see it as 5500rpm heads and a about 5500rpm cam. his combo is about perfect and i doubt there's much more in it without changing the cam and cylinder heads or at least some major port work on the heads. i've run that same Lunati cam in several different motors and none of them liked to turn much past 5500rpms. about 5800rpms was where i shifted mine with 4.10 gears.

71malibu406, what kind of numbers were you able to run with that 292 combo,could you give us a rundown on the whole package? You really sound like you know what your doing.