This question might seem a little stupid, so I'll apologise in advance, right now my 350 crusies at 70mph at 2800, I have a poston 118 cam and from a dead stop its not as torquey as i would like, I didnt build the motor so I dont know what the compression is, it really starts pulling great after 3200rpm. I already checked the timing, 12 deg initial and 32 total, which is where I was told to set it, already changed the dist curve springs, all adv in at 2000rpm. Already changed the springs in the vac adv, had a light spring in it, put the heaviest in it, its definetely better than before, but not how everyone brags about how torque monsters these cars are. So I was thinking about throwing a set of 390 gears in, alot easier to change gears than cams, any opinions are aprreciated. Car is used casually but do cruise on the highway, so was wondering do people whind these things up to 3000-3200rpm on the open road? any suggestions and input appreciated. Car is a four speed with 342 gears currently in it and 28 inch tall tires. Thanks again :3gears:
I would add a high stall torque converter... Something that stalls at about 2800 rpms would get you off the line well... The 118 cam kills the low rpm power and that is what you are feeling. Nothing wrong with 3000 rpms, except the fuel milage LOL. Your 350 should make peak hp at 5600 rpms so do not shift much higher than than. If you had a cam like a TA212 you would find it would be happy at 2500-3000 cruise.... This is a good setup for street cars and would not require the torque converter to get off the line well.
Which 4 speed do you have--wide ratio or close ratio? Makes a difference on which rear will be a good match. John
A happy cruise speed would be between 1700 and 2500 rpm's. At 3000 rpm's you are doing quite a bit of revving for prolonged highway driving. Now if you want a stop light killer, go the other way and look for the higher rpm's.
Another approach: keep the 3.42 and ditch the M21 for an M20. First gear will be about the same as if you put in the 3.90 and you won't raise your cruising RPM. John
A 3.42 gear with 28 inch tires are a great combo. That m21 has a 2.20 first gear. If it seems like you have too slip the clutch a little to much get off the line. Or it suxs driving in stop and go traffic. The trans 1st gear ratio is the cause. 3.42 * 2.2 = 7.524 ratio If you drive on the highway alot you want to keep the 3.42 rear. http://www.chevelles.com/forums/showthread.php?t=339713 Allen
Personally I'd keep the 3.42 gears and just swap the cam. I'd think the TA212 would be ideal for what your looking for as far as low end brunt, and highway driving.
Sorry I missed tha fact that the car is a 4 speed.... Unless you race a lot that 118 cam is not going to be thebest for a street car... I would look into a cam swap.
Yep think that 118 cam is coming out over the winter, maybe even the motor, Thanks for all the input.
