Im new here
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Im new here
Hi Im new here and my name is Jeremy. I have a 1987 Iroc 305 TPI, this winter im wanting to do a 350 TPI swap. I have the 350 block and Im wanting to bore it 30 over. I know i need new injectors, a new knock sensor, PROM, and ESC module. This is going to be a weekend car its going to see some track time. What is a good set of pistons? I found some L98 heads that i want to put on it. Dont know whether i should go with a 1.5 or 1.6 rr's. Which cam would be better the LT4 hotcam or the 3rd gen hotcam? Im also wanting to put on the stealth ram intake but that can wait. Im wanting to run it all with a th350 tranny, is it a 6in or a 9in tailshaft or does it matter? Thanks any other advice i should do to this is helpful.
Joined: Mar 2000
Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Is your 350 block a roller lifter block? If not, you probably don't want to mess with the LT4 Hot Cam (I've never heard of a 3rd gen hot cam). If you have a roller block, the LT4 Hot Cam is intended for 1.6:1 rockers, so that's what i would recommend.
The L98 heads should be worked over - new springs (and might as well go with new retainers while you're at it), valve guides cut for positive-type stem seals (which will allow proper travel to keep the retainers from hitting the top of the guides), and either pin the press-in rocker studs or have screw-in studs installed.
Speed Pro hypereutectic pistons are pretty popular. With 64cc heads, .020" compressed height steel shim gaskets, and block decked .010-.015" for ~.025" crown to deck height, the 12cc dish/relief pistons will yield a streetable 9.5:1 compression ratio.
The 9" tailshaft TH350 is the same length bellhousing-to-output as is the TH700. However, the distance to the mount is different. I believe most TH350 torque arm mount conversion kits assume a 6" tailshaft, but I'm not certain about that.
The L98 heads should be worked over - new springs (and might as well go with new retainers while you're at it), valve guides cut for positive-type stem seals (which will allow proper travel to keep the retainers from hitting the top of the guides), and either pin the press-in rocker studs or have screw-in studs installed.
Speed Pro hypereutectic pistons are pretty popular. With 64cc heads, .020" compressed height steel shim gaskets, and block decked .010-.015" for ~.025" crown to deck height, the 12cc dish/relief pistons will yield a streetable 9.5:1 compression ratio.
The 9" tailshaft TH350 is the same length bellhousing-to-output as is the TH700. However, the distance to the mount is different. I believe most TH350 torque arm mount conversion kits assume a 6" tailshaft, but I'm not certain about that.
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Joined: Jan 2002
Posts: 13,622
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From: Orland Park, IL
Car: 1984 Z28
Engine: SLOW carbed ls
Transmission: TH400 with brake, 8" PTC converter
Axle/Gears: moser 9" 4.11
you can buy a retrofit roller cam for mucho money, just get a flat tappet if you don't have a roller block. Also the TH350 torque arm mount conversion kit won't matter which TH350 tailshaft you run, since the trans mount and torque arm mount are in the same physical position regardless