Hey all. I'm planning a rebuild on my 77 W72 (y6) 400.I've got a bit of a dream sheet together and was wondering if some experienced eyes could have a look over it to see if I've made any rookie mistakes.
Scat 488 stroker kit. 4340 forged crank and pistons.
Comp cams stamped roller rockers. (Undecided on ratio but probably 1.5)
I've got a stock th350, 3.23 8.5" 10 bolt rear end and 28" tyres. The thing I'm getting stuck on is torque convertor selection. I want good street manners and avoid slip as much as possible. Without a dyno figure for the motor it's tricky as i don't know where peak power/torque will be.
Its not recommended to stroke up a 557 400 block because of thin main journal bulkheads. There are many posts where the stamped roller tip rockers over heat and fail at the pivot ball socket. For a couple more bucks get a full roller rocker arm from comp, crower, or harland sharp. Th350 is a tuff transmission and should do fine. 3.23 is a good street gear.. Upgrade if it brakes. A general rule of thumb on torque converters is to stall 500rpm's Over the low number of the camshaft power band. Cam looks a bit small for a 488.
There.. did i blow everything up?
Bull Nose Formula/ 461/ Q-Jet/ TH400/ 3.08 8.5 / R44TS.
Edited by - Blued and Painted on 29 Sep 2016 12:52:29 PM
Guys, thanks for the info. I'm kinda leaving towards keeping it a 400 now. I save 2k that way! So general consensus: the aforementioned setup, minus the stroker kit, but switch the stamped rockers for full rollers? Keep it 1.5? The advertised cam is from 1700, would a 2400 b&m tork master be ok? Forgive my ignorance, I'm English ;)