Rear End Fishtail

[Chevypoor]

Alright lets get the laughs out now, yes I am having some traction issues with a 305 sbc. For the last 7 years I have been running a peg leg doing the one wheel peel. After adding ball flange collector extensions to my headers and an x-pipe the one wheel peel started happening from a rolling start at say 20 or mph. Went to a posi and 3.73s thinking that would help. Now out of the hole she will hook fine most of the time. However with no power steering I do alot of rolling starts when turning left or right. Once I am almost straight probably going 10-15 mph I will lay the wood to her. Anymore than 75% throttle and once I hit about 20 or so about 4000 grand, the rear end will fish tale side to side and will not stop until I let off or shift into second (manually shifting a turbo 350) at 60-65 mph. Sometimes it is bad enough were the opposite lock is not enough to ride her out. Running 275 60 r15 on 8" steelies in the rear, Early Classic trailing arms, stock ride height, 34psi in the tires, polyurethane track bar bushings, Rancho shocks, one coil cut in the front. She is a long box with a 22 gal plastic cell passenger side of the box about a foot from the front of the box. Do I need more weight in the rear or a shock change? Should I move the fuel cell to dead center over the rear axle? I am planning on relocating the battery to box soon. Looking for any thoughts or help from you guys!

[Marv D]

I think I would be happy that the 305 is making enough power to create traction problems,,, serously!

The stroke of the 305 makes it torquey motor,, and it responds to mods as does any other SBC,, It is sounding like it's making good torque around 4000,, so need to look at the online shift calculators to put as much of that torque 'under the curve' as possible.

Trucks are NOSE HEAVY,,, Throw everything (including a spare kitchen sink) at the tailgate and you will be surprised. A spinning tire is not accelerating the vehicle. Concentrate on whet happens in the first 200' and let everything else fall where it may. You will be surprised how much quicker the truck can be with an extra 100-200 pounds over the rear bumper than it is (200 pounds lighter) and spinning for the first 200'

[Hollow65]

Pretty sure mine just kicks to the right once in a while. For the most part it tracks straight. I have a fuel cell centered on the bed and right at the tail gate. Also the worlds heaviest tonuecover. I'm sure on the spelling. I am supposed your 305 is giving you traction problems. Sounds fun as hell, be safe though.

[Ont67shortbox]

drop the tire pressure down try 28-30,Marv is right a 305 breaking loose a 4000 lb truck is not a bad thing

[PGSigns]

Fuel cell needs to be as far back and in the center as you can get it. Along with the battery and the for mentioned kitchen sink. That convertor is flashing up when you stop it and with little to no weight on the tires they just bust loose. On days you want traction (after moving weight) drop the tires to 26 or so. One more thing to consider is a lot of street tires have a very hard compound to make them last. This just make some tires impossible to hook.
Jimmy

[Chevypoor]

Thanks guys! I will shift the fuel cell back and throw the battery in the back hopefully soon as well. I will also try dropping the air pressure.

I have put her on a diet- no power steering, no power brakes, heater core delete, no spare, no rear bumper, no horn, etc. Hoping to yank the radio and speaker soon, still with my fat but she still weighs atleast 3800-3900 pounds.

The 305 has surprised me- the truck originally had a 350 in it but it locked up- another long story! I had the 305 in the corner that I had bought for $50- the guy I bought from did not even now it had bored .30 over!

The look on the guys faces at the cruise ins and car shows is priceless. They hear the truck come in and come over to check her out thinking it is a 383 or 406 and when I tell them its a little 305 they are shocked!

I have had this motor on the chassis dyno twice. The last time after two runs we pulled the plug when she developed a rattle. Turned out to be a couple of loose converter bolts! I was also seeing only 3psi of fuel! She made 252 horsepower at the tires with no fuel pressure and when I was diagnosing the rattle I checked the compression- one cylinder was 185, one 180 and the rest 155-165. When she was new they were all 185-190. The ol girl is tired- I have beaten on her hard over the last seven years.

I just installed a Holley Blue and that has made the fishtailing worse. I think a healthy 305 built to the same spec as this one would be 265-275 hp at the rear tires.

[Ont67shortbox]

if your taking it to the track,when you move the battery,don't forget you need the cut-off switch