I currently own a 305 TPi and want to turn it into a 350 TPi. I was lookin on SDPC and found two possible engines. One was the L31 and the other is the L98. The price diff is like 50 dollars. The Link is here if u want to look at it,
http://www.sdpc2000.com/cart.asp?act...tart&catid=514

My only question is the L31 is a 4-bolt main so which block is the better for around 400 horses. This is what i plan to obtain stayin with the TPI. are the two blocks compatible with the TPI?

------------------
1986 Metallic Blue IROC-Z
80k miles, 305 TPI
Mods:
-Edelbrock Hi-Flow baseplate
-Dynomax Cat-back
-gutted MAF
-K&N's
-airfoil
-shiftkit

 

Also, what are some good heads to go along with that...I was thinkin either the World Sportsmans or the Airflow research ones...what u think

------------------
1986 Metallic Blue IROC-Z
80k miles, 305 TPI
Mods:
-Edelbrock Hi-Flow baseplate
-Dynomax Cat-back
-gutted MAF
-K&N's
-airfoil
-shiftkit

 

Air Flow makes the best heads you can buy for **TPI** engines!! just look around at what people with them are running

------------------
88 Iroc-Z L98, rebuilt T5, ported manifold and plenum, built 355 shortblock, ZZ3 cam, Ported S/R Torquer Heads (2.02/1.60), AFPR, Hedman 1 5/8" 3" collector, 3" y pipe, !Cat, Edelbrock Catback, 3.42 gears WAITING FOR TIMES!!

 

For $50 you might as well get the 4 bolt. Both will work fine for your TPI and I highly recommend the AFR heads as well. That brand new shortblock should provide good service.

 

Both have cast, dished (13cc) pistons. Okay to handle the power, but less likely to make it.

Of course, you could get a set of flattop hypereutectic or forged pistons and have them pressed onto the rods for less than the ZZ4 shortblock would cost you. But then, the ZZ4 is also going to have a forged crank and PM rods, much more capable than either the L31 or L98 for power-handling.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4, 2300 stall TC. Ported World 305 heads, Crane PowerMax 2050 cam. ZZ3/4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster 80. 2.93 limited slip. Spohn SFCs waiting to be installed. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
57 Bel Air, my 1st car. '66 396, 9.7:1 forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 700 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).