I have a '97 LT1. Here are the mods. What TB should I go with?

-Line bored to a 355
-Heads and intake portmatched
-220/230 CC at fifty lift
-upped compression to 11.25:1
-Hypernuectic pistons
-upgraded valvetrain (not sure of the details)
-Pacesetter LT's
-Pacesetter offroad 3" y-pipe
-3" exhaust with 1 chambered muffler exiting quad Borla tips
-spraying about a 120 dry kit

What TB should I go with, 52mm or 58mm

 

If I remember right I read on the board once that the only engines that REALLY needed the 58mm TB were those that were bored and stroked I.E 383,396 just because a 355 didn't need that much air especially if you didn't have the intake bored to match, so you wouldn't see much gain. Personally I'm going with the 52mm TB.

 

52 mm

 

What #'s are you running, on the dyno, and at the track????

 

I look at it this way, the LT1 intake manifold is essentially a Hallow box. Given the cam and cylinder heads its going to only let so much air in. Wether its a 52 or 58mm tb, your combo is only going to let so much air in.

THe only issue with a 58mm tb is that you need to BORE the intake manifold so you actually have a 58mm port. Stock is 52. So this goes from a bolt on and go job with a 52, to a major job with the 58.

I always plan ahead. So do a 58 now, dont bore the intake. And if you go bigger on the cubes or go forced induction. Then your all set.

Build for the future, why do the job twice.

I ahve a 58mm BBK.

 

I'd go with the 58mm. Like the other guy said just do it once.

 

To be honest with you I haven't dynoed it yet or put it on the track, I'm having some sort of spark/ignition/electrical issue and I'm losing mad power, I can only break tires free in 2nd gear, and not for long

 

you dont need the 52 now, but you most likely need it later, as said before upgrade once.

 

I just got a nice 52 but might sell it to buddy who is staying milder and go with a 58. I thought I had to port the intake for the 58 blades to work right.So you guys are saying I can run the 58 right now and then port the intake later ,likely when its off the car next year when plan on installing LE2 heads,kooks headers and the cc305 and 1.6 nsa rockers sitting in my spare room. LE recommends the 58 tb for his stage 2 sets ups I think even on stock displacement engines. And figure he knows his stuff. But the price is the same so if you can just bolt it on an unported intake then might as well I guess.

 

yes you can bolt a 58mm tb on your stock intake. There will be a 3MM lip all the way around which could cause some turbulence but at least you would have a 58mm tb later for when you do port it.