hello again, i'm still trying to figure out this 454 TBI swapage. this morning i took off the manafold and spilled some radiator fluid into my engine... wonderful... hopefully i can change/flush the oil and it'll be ok? >_<

i've been looking through past posts and thinking about how the 305 doesn't need a bigger TBI to make 300+hp. if this is the case then boring my manafold to 2" for my new TB might not be such a good idea? although this isn't a 305 motor, but a crate vortec 350. it should be making 330hp.. although you can never know once its mounted within your application. for me its rather stock other than flowtech headers and true dual exhaust, so its got plenty of flow out the back. in theory adding the bigger TB will give me the extra air i need to let this motor kick some ***? but if i'm wrong... then i'll be stuck with a f*cked up $300 manafold and a bad running motor.

i guess what i'm looking for is somebody to assure that they've done this before, and it'll all be ok. if somebody knows of a horsepower range for the 454TB perhaps? *** i hope this isn't an overkill... (although if it is then i've got an excuse to beef it up more )

heh.. i can't wait to have to put it all back together again. some of the places for bolts, valves, etc. are very hard to reach with a wrench; its the old PITA 'quarter of a bolt turn' at a time... lol

thanks guys you've been nothing but good help. i'm doing my best to learn as much as i can while i proceed. i'll let you know how things turn out monday, when my manafold will be ready. (although something tells me that i'm being too opimistic lol)

 

For a crate 350, you'll definately want to go with a 454 unit or a holley 670. The tbi on a 305 barely flows enough for mildly modded 305. I had to bore and taper alittle material off of my edelbrock performer rpm to fit the tbi on it. It's no big deal, if you decide to switch to carb or something later you could most likely sell the manifold to another tbi'er for close to what you got in it.

 

i took the manafold into the machine shop. they said because its a dual plane intake that one of the bores would be cutting close to the air channels. he said hed do the best he could but if there are ledges left within the bore it could create turbulance and cause some of the cylinders to run lean, possibly killing the motor. apparently a programming genious could compensate the injectors if the problem comes up... but who knows.

usually you guys just use a regular carb manafold and slap on the adapter plate. with my case this was already made for TBI, and isn't able to be bored to 2", but he would 'do the best he could'. he'll probably bore just enough to let the butterfly open and just merely shave off the manafold bores to be safe.

another issue with my manafold is that the 454TBI is slightly bigger than my old one, so we're going to have to make a custom spacer in order to keep it sealed up right. (rather than just using a **** load of RTV :P)

let us pray that this 'jimmy riggin' doen't cause too much turbulance and screw up my engine.