Does anyone know how big the stock throttle body is on an LT1? I do know that the plate from the throttle body to the intake manifold is 52mm. Anyone answer the question?

 

48mm.

 

this man speaks the truth.

 

Thanks fellas....but.....I recently bought the SLP LT1/TPI airfoil, haven't installed this yet. If I buy an aftermarket TB, can I put the airfoil on the new aftermarket TB?

 

No it should come built in, at least my holly did. So you won't need it.

 

They all usally come with Air foils, any after market one atleast

 

With the mods listed in your signature, you won't see any gains with a larger TB. Spend your money elsewhere.

 

Everything I've read agrees with this advice....

I just recently watched a program where a 94 Z28 was hopped up. They used a dynojet as they added new parts. I noticed how careful they were to mention brand names and apparently to avoid it when the parts used weren't supplied by a sponsor. Just something to be expected I think. Anyway, when they put the new 52 mm TB on the engine they combined it with a piggyback performance chip to mask the fact that the larger TB made no difference on the dyno. The car gained 8 hp with the new module (and TB ).

 

Intake bores are actually 54mm, other than that I agree with everything said. Hell I went from an airfoiled 48mm to a 58mm on my mildly cammed car and noticed no topend gains. I think most of those who do claim gains from TBs on mild setup are confused by the drastically changed throttle response.

 

How about 1"=25.4mm

 

The stock TB is dual 48mm bores. I did notice that the hot cammed LT4 used the stock 48 mm TB. 93ZTed

 

The LT4 was not "HOT" cammed it had a LT4 cam much smaller than the LT4 HOT and if you want to talk engines that use this TB so do the Ramjets both 350 and 502.

 

The last ram jet 350 I saw used a single bore like a stock LS1 TB.
http://static.summitracing.com/globa...12499120_w.jpg

Ill be that would make a good LT1 manifild if someone modded the crap out of it.

 

I went searching and yeah the 350s have the single LSX style. The 502s do have the LT1 type though.

 

Just measured the stock LT1 intake from my 94, and the throttle bores are EXACTLY 52.00mm diameter. There's a small chamfer, but the 7.75mm depth of the bore is 52.00mm.