321 or 347 Which is a better with an S-trim (15-16 lbs boost)

[OneBad93LX]

I need some help on SBF knowledge on this one...

I bought my 93LX with the 321 installed already. So I took the guy's word for it. I spun a bearing last time out at the track. I finally got the engine out and torn apart.

Here's my findings:

Stock crank (E7AE-AA) with .010 under mains and 1.990 rod journals. The rod bearings are a Federal Moguel 3765ra .25mm.
Rods are an H-beam Rod with part # CRS-5400-F.
Pistons are Probe # LW40

I spun #1 and 5 rod bearings. #1 & #5 Rods are blackened and won't be reused, I'm also not using the crank. The block and all pistons are fine.

I also have a good 347 rotating assembly on hand.

It consists of a Eagle 347 crank, Eagle H-beam 5400C Rods with SBC rod journal size using a 6cyl chevy rod bearing. and a set of Ross XL400 pistons. I was told they were a 11.5-1 piston.

Here's my issue... I'm going to run an S-trim with a Reneage pulley (hoping for 15-16 lb boost) I'm also going to use my TFS heads. I will be using a C4 with a 4500 stall.

1. Was the engine installed in my car a 321? What's up with the 1.990 rod journal size. Is this from the off-set ground crank?

2. Should I build the 347 and buy lower compression pistons, and use the 347 crank and rods?

3. Should I just buy 2 new rods with the smaller rod journal size and buy a new crank..and keep the 321ci. I want to stay away from stock. If I do get a new crank.. which one do I order?

Do I have any other options.. with what I have?

I was real happy with the performance of the 321. I ran 11.2 @ 127mph with a PowerDyne BD-11 (9lb boost). I'm concerned about blowby with the bigger blower..but that's for another thread...

I really apprecitate anyone who has taken the time to read this and answer!!!

Frank

[ray95]

Well if it was me in that situation, I would go with the 347 and get a well known GOOD set of low comp pistons. I would also try and get a good block as well. Good luck.

[OneBad93LX]

Yep.. That is what I am after a good set of 347 low compression pistons... the block will have to wait until next season... I'm not racing it this year.. just playing.. so I won't be to hard on it... should make for one mean street car...

[OneBad93LX]

I called CHP and they have 2 different pistons that will work for me. One has a -24.0cc dish and the other has a -14.1 cc dish. The -24.00cc dish works out to be 8.1-1 compression and the -14.1cc works out to be 9.1-1 compression. What would you do?

[ray95]

The 347 should be ok with 8.1-1 compression. You'll still have low end torque and the motor will be able to handle more boost with 8.1-1 comp. Well that's what I would do. With a good tune, you should be a monster on the street. What H/C/I are you going with?

[OneBad93LX]

Heads: Twisted Wedge - Stage 2 ported from Fox Lake
Cam: F-cam
Intake: Performer RPM with 75mm tb 75 mm meter and Anderson Ford Powerpipe...