Help with 355
First I want to thank everyone for the wealth of knowledge I have received from reading all of the different threads on this forum. This forum has allowed me learn so much. I cannot thank everyone enough!
I purchased a 72 Chevelle with a 355, 400 turbo transmission and 10 bolt rear end. I was not given very much info about the car except that it was built for the drag strip, had some aftermarket cam, and the transmission had a shift kit.
I have done a lot of work to it. I’m trying to get it more of a street car, but still with as much torque and speed as I can. I rebuilt the rear end with 3:73’s, Yukon DuraGrip, Motive Axles and an aluminum rear girdle. It had 4:11’s and the spider gears welded. I also rebuilt the Holley Double Pumper. I have no clue what cfm it is. But, I’ve had a terrible time getting it tuned correctly. The car had a noisy gear drive that I had to get rid of, so I put a double roller timing chain on. It drove me nuts. After installing the timing chain, I was able to actually hear to motor and thought it was missing while I was trying to get the carb tuned. I got it good enough for the time being because I ordered an Edelbrock Performer RPM Airgap intake. I figured I would check the cap and rotor, which is a pro billet MSD powered by a 6AL box and Blaster 2 coil. It was very corroded, so I cleaned it up and put it back on and the car wouldn’t start. It backfired and the carb had a small fire in it that went out very quickly. I replaced the cap and rotor and still no start. I checked for spark with an inline tester and it was an orange, so I figured maybe a weak spark and replaced the coil. Still nothing. I’m thinking maybe the pick up is bad? I checked and the rotor is pointing to the #1 cylinder at TDC. I pulled the distributor and it looks fine except for some corrosion on the pick up. Anyone have any thoughts or ideas on this?
With the new intake on the way and the distributor already out, I just pulled the Victor Jr. that is on the motor. I’m replacing it because I don’t think I need the 3,500-8,500 rpm range for mainly street driving. I found out that I have the “Turbo” 340292 heads with 1.6 intake and 1.5 exhaust valve roller rocker arms. They look aluminum and pretty new. It looks like the heads were made in the 70’s, have a 64cc combustion chamber, 2.02 intake and 1.60 exhaust valves. My question is should I just replace the camshaft with a new one that I know the actual specs of? At idle, I was getting tops about 8” of vacuum. The vacuum gauge was never consistent. I’m wondering if the intake had a vacuum leak because I couldn’t find one anywhere or maybe it was just the cam. I don’t think the cam sounds that aggressive. If I replaced the cam, what would be a good one to get with the “Turbo” heads, Airgap Intake (1,500-6,500rpm), Holley Double Pumper, 400 trans (shift kit, stall converter at or a little below 3,000rpm) and 10 bolt 3:73 posi rear end. I would like it to match the 1,500-6,500 rpm range of the intake and be good for as much street performance as possible. I’m not concerned about the lopey sound. Are there certain specs I should be shooting for?
I look forward to receiving some feedback for all of this that I have going on. I truly appreciate everyone’s help!! Again, thank you!!