Anybody know of a bigger bolt on throttle body for TBI 305s? Will a stock throttle body from a 350 tbi bolt on? Just looked through Summit racing and can't find a thing! My TBI 305 is bone stock. I just want bolt on stuff no adapters for fittings or stuff like that.

 

The 350 TB will definitely fit because you already have one. The 305 and 350's use the exact same thottle body. The injectors are bigger on the 350, but if your 305 is totally stock the bigger injectors aren't going to help you.

Carefully read the "stickies" here at the top of the forum for some tips on squeezing more power out of your 305 without blowing too much dough. The stock exhausts on the 305's are pretty bad, so that is the first thing you should look to upgrade. You can also increase the flow of your intake system pretty easily, including your current TB, this is all covered well in the stickies.

Those modifications won't require bigger injectors, but to get the best benefit you'll need to reprogram your chip. Also covered pretty well in the stickies, although it takes a while for all the info you need to absorb to be able to make your own chip soaks in. For me it took a couple months of reading posts here before I got a reasonable grip on the process, but there are a lot of sharp guys here to help you over trouble spots.

With those three changes (exhaust, intake, chip) you should be able to squeeze 20 more HP out of the engine, but I'll let you know in a little while, I'm in the process of doing these exact same mods to my L03/305.

If you want more power than that, next in order on the list would be cam, headers and then new heads and at that point you would probably need to go to bigger injectors and have your TB bored for more flow.

Me, after I get comfortable tuning and burning chips I'm going to punt on the 305 and swap in a stout 383 and have some fun smoking imports with my big sleeper TBI wagon.

Good luck-

Paul T.

 

dude check out XtremeFI,, they have what you need,,, I use one from them,, it`s a 2" bore yielding 750cfm, that and bigger injectors and it only cost like $250 rocks less the injectors,, runs like raped ape!!!! matter of fact I`d say the combo I have is good for around 50-75 hp on a stocker, the factory throttle body is good for only about 430 cfm, I dont think thats enough for even a kia 4!!!

 

Actually, the stock throttle body is good for 490 cfm.
A stock 350 only uses about 450 cfm. It's not a restriction on a stock/mildly modded engine. Until you've changed your cam or heads, a stock TB with the Ultimate TBI mods (520 cfm) is not a restriction.

If you haven't made any other changes, changing the throttle body won't give you much of a gain in power. Like titchener said, I'd recommend changing your exhaust, chip, and intake before you change the throttle body.

 

Stay away from that seller, he is a disonest THIEF. All his statements about his products are
What he is doing on ebay is called FRAUD!

Do lots of reading and serch on this forum and you will find out that your stock tb + injectors wil be fine even for 300hp.

 

IMO by the time you get all the ultimate TBI mods and spend all that money and time you could just have bought a holley TBI and got it over with. They work perfect with stock and yes they cost some money but it takes time to build an ultimate TBI. And if you get the intake too you kill two birds with one stone.

 

You don't need a bigger throttle body yet. I bought one of those 46mm tbi from xtremefi and while it does work you'll need to tune for it to work properly. my car had a HUGE bog when I'd floor it with that tbi on.Then again my Edelbrock manifold is bored out to so that didn't help. Hell I'm thinking about selling the damn thing because I put a reworked stock tbi unit with ultimate tbi mod's done by yours truly.

 

Ya you`ll have problems with it if you dont have a tune, thats for sure,but well worth it, in my experience with XtremeFI,, it was nothing but pleasure and the product is great! way cheaper than the Holley, besides the fact that Xtreme offers a 750 cfm and Holleys is only 670, plus it uses ALL of your factory harnesses, seals,injectors,and hop ups, also, I trust the factory injectors as I ve heard bad stuff about Holleys, also,, since the throttle body inj. dosnt get the respect it deserves, most people throw them away! which is why I have a box of fuel inj. all different ranges of lbs hr! so I wont have that to worry about that for a while,, I dont know, since my experience with Xtreme was nothing but good, I think that route, pound for pound, is the way to go, and I did study the others, turbo city, cfm tech,and Holley, I feel thats the way to go!