87Aerocoupe

Hey folks I have a 97 Z28 with a tired engine and I also have another LT1 in an unfinished project car that has a Comp 230/230 @ .050 .56/.56" lift cam, double roller chain, csi wp,new roller lifters and a new Canton pan, pump & pickup. I want to do a mild 383 build using all of the new parts in the project motor along with a Scat 9000 cast crank, Scat 6" 4340 rods and forged Mahle or SRP ft pistons. I'm also going to do a mild home port & polish job on the stock heads & intake with 2.0/1.56 stainless valves, Crane dual spring kit, 3 angle valvejob, bronze guides 7/16 screw in studs & guideplates with Comp 1.6 rr's. I also have AS&M 1 3/4" mids, fully built 4L60E with 2800 stall & 3.73's. The question I have concerns whether I should spend the extra money for splayed 4 bolt caps or just install a 2 bolt main girdle like the one Jegs sells for the LT1?

I know the Ford guys build potent motors with 2 bolt mains and main girdles, so what do you guys think is appropriate for a budget daily driver occassional trip to the strip?

rskrause

I don't think you need either.

Rich

87Aerocoupe

Not even if I want to try a 125 or 150 shot and shift at 6500 rpms?

Don 97 SS

Chevy guys can build potent motors with two bolt mains, too.

SS RRR

If you're going to spray it then yes I'd do something other than just the stock 2-bolt.

Injuneer

If you think the cast crank is adequate, there's no reason for the 4-bolt mains or a girdle.

87Aerocoupe

Thanks guys I have been rethinking the reason for this motor, it's a stopgap to hold me over until next summer when I can do a fully forged and built 383 with good heads etc, this way I can have some reliable fun this year. I just don't want to beat on a shortblock with almost 90k on it and since I have the spare motor from the other project I figured why not freshen & strenghten the bottom end and build a budget 355 for now. I found a GM forged 1053 crank for $550 although I see many of you have had success with the stock crank and I want to use either Scat 6" procomp 4340 I beams with 7/16th bolts or Eagle H beams with either Mahle or SRP forged ft pistons along with the CL77 armor coated rod & main bearings. ARP main studs and head bolts with the main girdle should make for a stout enough bottom end to have some fun without worries, what do you guys think?

SS RRR

If it's just something to tie you over then I'd put as little money into it as possible. Maybe still a girdle. Caps, especially 4-bolt are expensive.
The way I'd do it is either use the original short block or refreshen it with stock bearings, rings, ARP rod bolts, stock pistons and rods (stock LT1 rods can take masssive abuse).

87Aerocoupe

Cool thanks for all of the advise and help but I recieved good news today the machine shop I use called me and told me my 383 will be done by the end of June so I'm going to sell this short block with the cam,timing setup and oil pan. Then use the CSI ewp and lifters on my 383.