Hey guys I hae a 305 tbi motor in my dads truck and i am taking the motor out of my 89 firebird and putting it in his truck, It has flat top pistons, vortec heads, and a xe-274 cam but i am taking that out cause it know its not tbi freindly, what woudl be the biggest emission legal cam i could swap in there and not upset the computer?? He is selling his 03 ran with the hemi for money reasons and id like to give him around 320-350 horse if I can without going to carb, cause if carbs wut i have to do its gonna be more like 425 horse lol. thanks guys

 

once u mess with internalls or manifolds, u really should do computer work. id say do a LT4 cam, 305 TPI (081) ported heads, chip work, and a edelbrock preformer TBI manifold then the exhuast and open element to support it

 

its already got Vortec heads on it...changing would be nuts lol...

 

Just stick a carb on it man, 425 hp > 350 hp

You're going to want to dig into the computer for whatever combo you decide to run with the TBI, just like you'd have to jet the carb.

 

sry i didnt kno, thought u had the stock swirl ports

 

Would you use a stock carb with unknown jets, and plan on not changing them no matter how much you changed the motor? Then why would you do the same with FI?

I can understand if you just don't want to put the time and effort into learning how to do your own chips. Don't waste your time trying to make TBI work if your not willing to put the time and effort into learning to do it right.

 

well i wanted to know how much the computer can learn wihout freakin out, I know its not as much as a stangs fuel injection, but im not building a race car, just a truck with some power so it can pull my 23 foot boat.

 

no offense to 305s but, from experience i would rather take a 292 inline 6 for pulling over 305s (then again if you build your 305 up that's a different story).

Anyways so far i'm pretty sure the only things you can do to hte engine without modding the chip is, headers, open element or some other kinda of c.a. intake, headers, cat back, highflow cat and possibly a different manifold i've heard both ways on that.

i've also heard of people putting mild cams in them without to ill of an affect but, if your willing to endanger the driveability of your fi motor then it's best just to go carb i.m.o.

more than likely your driveability will go down the toilet and you will get over rich or over lean mixtures with anything like a cam swap or such but, take this with a grain of salt because, this is only hear say.

the only mods mine has is a open element and flowmaster catback (tellya the truth it still doesn't run all that great) it's running rich right now and the fuel pressure is bleeding off lol.

O well it beats the last vehicle (the other brand truck with a 300-6 lifted with mud tires) (definetly not good on the driveability factor).

 

Without computer work, id get a very small flat tappet cam. No more then 200 degrees of duration at the intake. You could probably get a copy of a '929 cam or something. I had one in my 350 and all it did was make torque with that cam. If its not an aggressive profile then you can also slap on some quality steel 1.6 ratio rockers from comp cams or something to take advantage of the high mid lift flow of the vortecs. This and a good, intake, air cleaner, and a 3" exhaust with headers will help that motor lug a boat around. Its unlikely youll get 350 HP and still be able to pull a boat while getting good fuel economy. Id estimate that Youd probably have around 200-225 out of the 350. But, itll make its peak torque around 2000-2500 RPM. Chip work would really help, but this engine should be a little closer to the stock VE tables, so itll probably do ok.