My brother inlove with the TPI going into my truck went and bought a 305 TPI out of a '89 IROC-Z. Its already a big step up from the 2.8L in his Blazer but he wants more about 300HP more. How can he do this?? Heads , Cam , Valvetrain, Intake?!? The 305 can't use the same stuff im getting for my 400TPI it would be too much , so I'm kinda in the dark here please help me!!

 

If I can get about 300HP out of my car with the mods now, of course you can get 300+ out of a TPI 305 N/A. A good set of heads, cam, tpi mods, exhaust, ignition and you'll be well over 300.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End

Current Mods: LT4 Hot Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

7.5" 10 Bolt with 3.42s soon to come!

 

Your brother in law needs to take his 305TPI and change these items:

1) Port the plenum, add aftermarket runners, and an Edelbrock TPI base.
2) Port & polish the heads or better yet, buy AFR 180 aluminum heads, shaved to 54cc, with 1.94 intake, 1.60 exhaust valves. Keep the pistons .029" in the hole, and run a .015" steel head gasket.
3) good quality headers with 1 5/8 inch primaries, running to a 3-inch mandrel bent exhaust. I like the Hooker Aerochamber.
4) Really good cam. Try Comp Cam's Xtreme energy hydraulic roller cam. They have a marine cam with 218/224 degrees duration, and 112 degrees lobe separation that'll work great. (this is like, the third recommendation I've made for this cam tonight!)
5) 2500 RPM torque converter. I'm using a $160 converter from turbine technologies, and it's good for 300 to 325 horsepower.
6) Good gearing. He'll want 3.42's or 3.73's for sure. The SLP takeoff Torsen differential is a bolt-in with 28 spline axles, if he wants a cheap posi.
7) good radiator from Griffen. there's no sense overheating this machine!
8) Computer programming. Once its all together and running, have him make an appointment to throw it onto a chassis dyno for some custom tuning. this will make a night & day difference in the streetability as well as top-end power!


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Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Turbine Technologies 2500 stall converter, underdrive pulleys, Crane Hi-6 & more.
1.05g skidpad verified.
New best E/T! 14.039 at 100.82 MPH in 41 degree air at Stanton, Michigan.