Irocdriver89

switching from tbi to carb can i still past smog in cali, it's a 91 maro 305 with tbi on it right now i'm going to by all new parts so everything should be brand new also how much would this switch effect gas mileage high rise intake and a holly 600 carb.

ME Leigh

No they have visual inspection there. You cannot really replace anything. You also have to use a newer motor if you were swapping.

Irocdriver89

ok well thats out of the question

Dave89IROC

yea, the only way to swap to a carb would be if the car was originally avalible with a 4 barrel(I.E., 87 and older third gens)

klumb15

what about swapping to a LT1 6 speed or something....can you do that and pass emissions???

Dave89IROC

yes he could, the basic law is this,
it has to be the same year or newer,

of the same type originally avalible in the car(v6, v8, ect....gas, diesel.......)

has to be a passenger car engine(not truck),

and, it has to retain all of the emmisions equiptment that came in the car the newer motor came from

there is other stuff, you may need it inspected, ect., and it has to pass the sniffer(duh)

PyRo9862

I think you could get away with it. The stock aircleaner fits the carb right? I have never seen them take the aircleaner off, other than that how do you tell the differance between a tbi and a carb? Just leave the wireing harness laying around.

Dave89IROC

as long as he leaves the other emmisions stuff on, and it will pass the sniffer for a TBI

Irocdriver89

is the tbi that restrictive that i can not pull the same power from that as what i would get with the carb set up. i always thought that fuel injection is way better than a carb set up.

Dave89IROC

you could go with a Emissions legal(EGR) 4 barrel intake, an adapter plate and a Holley/454 TBI, that will give you approx. 650-670 CFM flow, that is a major improvement over the stock intake/TBI(approx 370-400 CFM IIRC)

Irocdriver89

how would it be to go with the high rise intake with the stock unit until i can get the other set up. that tbi unit is very expensive. but i can go pick up a intake today with egr what power gain do you think i would pick up. i have flowmasters and maybe some headers to go with the intake where would my power be at a guess. 195 with 295 torque stock thanks for the help.

Dave89IROC

you should notice a seat of the pants difference with the aftermarkect intake and stock throttle body, how much, I couldn't say

KISSAlive!

This is just a suggestion, but if the TBI is working well, I'd leave it alone. I have a 91 RS with the 305 TBI, over 160,000 miles and still trouble free. Never been rebuilt or modified beyond headers. Starts up in the summer and winter with no fuss, gives decent MPG, doesn't burn oil, and still has a nice growl to it. It's no street terror, but still holds its own.

If you really want to upgrade, save up some cash and get a 350. Don't know about emission laws, most places here (Kentucky) don't test. I'm pretty sure the L98 engines from a 'vette or F-body would pass a smog test if everything was functioning. You could probably pick up an old IROC or Formula with those engines cheaper than buying a new crate motor and have a parts car to spare.