Hi guys,

Well I am in the process of swapping my tired 305 to a 91 corvette L98. What my question is, is with the aluminum 58cc vette heads, and a TPIS big mouth manifold, 52mm TB, and AS&M runners. What cam do I go with? This will be a Speed density set up with a custom chip from Ed Wright, which will be burnt once I know my setup completely...

Also I need to know what stall converter came stock on this vette tranny 1991 700R4? If this stall isnt good what converter do you guys recommend and what stall? maybe a 2800 I was thinking? I would also like to get a new flexplate for the motor while its out, what do you guys recommend a good name for the one-piece rear main 350 block?

For the cam I was thinking along the lines of the LT4 hotcam, the ZZ9 or a few in that range from Comp cams. Anyone have any input? I would like to go as big as I could without causing vaccum problems, and again this will have a burnt chip to go along with it! Thanks for any help guys!

 

Have a bud with a ZZ4 (same aluminum heads), ZZ9 cam, Big Mouth base & runner, 52mm TB, SD, CNC ported heads, 1.6 roller rockers, shaved & decked to about 11:1 static CR. He has a 2000 stall converter, it isn't near enough. Vette's stalled ~1800, IIRC. 2800 should do well.

He kept getting & returning PROMs, trying to get it right. Would have spent less and probably had better results if he had just gotten his own burning equipment.

 

Theres nothing like a good book. Try reading something like "Chevy TPI Fuel Injection Swappers Guide".....Lots of good tidbits of info to get you thinking in the right direction. Also cam recommendations , If nothing else, this book has a list of manufacturers/sources with address & phone numbers to call for Professional data, and information.....Like TPIS.
As far as the torque convertor from the 91 vette L98....this was most likely a "B" or "C" code converter...which also was available in all 350 powered F bodys, like the GTA, Formula350, or Z28 wL98... it was a 2000rpm "High Stall" factory converter.....look at the ID tag(sticker) on the converter itself...you will see a 4 digit code and an 8 digit number.....in the 4 digit code you want to look at the 2nd letter..... it will be a "B" or "C"...(= 2000rpm)...

FYI for other factory converters.........Goes like this:
GM 4 code system(code 1 & 2 most important)
1st digit(Year) 2nd digit(Stall)
C=early 700r4 w/27 spline G, H, K = 1200-1400rpm
D='85-up 700r4 w/30 spline E, F = 1611-1651 rpm
H= 4L60E (will fit 700r4) B, C = 2000rpm

 

Thanks for the ideas guys! So I guess I am going to go with a 2800 stall for now. I think the ZZ9 would be a good choice with 1.6rr's. How compression wise am I looking at with the 58cc vette heads? Will I be able to run 93 octane pump gas?

 

Use a scan tool to see if you are getting any timing retard/engine knock will a lower grade fuel. Start with 89 and try up or down depending on your results. Use up most of the tank between tests. You want to run the lowest octane rating that doesn't detonate. Higher octane rating when you don't need it makes you loooooze power.