I have a 87 Trans Am 5.0F TPI. I just replaced the cam lifters and had the heads reworked. Well after only two days of driving it on the third day the enginge started to knock and before I got it home it shut down on me and would not restart Well the next morning it started but knocks real bad esp when It's reved up. I belive it in the bottom end and instead of fixn the 305 I can get a 350 short block from a freind of mine for free it just needs to be cleaned up and new bearings. Now if I install this 350 will all I need to make it work is a computer chip from a 87 350 TPI Trans Am. The engine is a 93 LO5 350 and I'll use the cam that I bought for my 305 in it

 

Did the 305 to 350 swap on my Z 8 mos. ago. Don't need to change chip, will work great as is. You can if you want but not necessary. I upgraded to 22# injectors and still didn't change my chip until recently which I only did to run cooler (see signature).

Good Luck!

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'85 Z/28, 355 TPI w/ Crane Compu-Cam 2040, Crane adjustable fuel pressure regulator, 22# Injectors, TPIS Airfoil, K&N filters, Hypertech ThermoMaster Stage 2 Chip for '85 Vette, 160 Degree Thermostat, DynoMax Cat Back Exhaust, Rebuilt/Updated 700R4 w/shift kit, 3.23 posi rearend.

'69 RS-Z28, DZ302, stock show car.

 

If you want to retain the 19 lb injectors, and the fuel pump will keep the pressure there @ WOT, you could increase the fuel pressure to 50 - 55 psig & the spray pattern will improve, as well. Make sure the O2 sensor voltage is in the high 800 mv to low 900 mv range @ WOT. TPIS (612-448-6021) may know the details on the approximate correct pressure required for 19 lb inj on a 350.

Tim

 

i still use the #19 injectors with 47psi fuel pressure. the car falls on its face if it is 49psi or above. i get around 850mv @WOT. like DW said, you don't need the chip. i made the mistake that i needed on but have swapped them and i haven't found any noticeable difference.
the knock sensor is different between the 305 and the 350, though. i still have the 305 one but plan on changing it here soon. if you want a chip, though, i have a JET chip that i aquired from someone switching to carb. i will sell it for a decent price if you are interested.

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87 iroc-z 355 TPI 5 spd. 51006 SLP cam adv. 4* (106.5* centerline)
hypertech stage II chip/ 160* stat./ Airfoil, accel AFPR
3.45 rear (stock)
Flowmaster, K&N w/ hacked airbox
14.38@100mph 2.2 60'
removed MAF screens

 

Thanks for the info I'm glad to here that I don't need a chip saves me the money. One more question. How about heads. I was tolded that I can use the 305 heads all I have to do is install pistons for a 350 that work with 305 heads the guy said there cut different to work with the 305 heads. Is this true and would anyone recommed doing it or has done it? I just spent 275.00 on getting my heads done when I changed the cam I only got to put less than 200 miles on it before the bottom end went out.

 

i have the 305 heads on my car and they work pretty good. i put 1.94 intake valves in, unshoulded the intake valve, 3 angle valve job, and pocket ported them. if i recall, they came out to 62cc chambers and i think .035 deck height. my pistons were dished 12 cc's, though, too. hope this helps ya.

 

All injectors are rated at 43.5psi of fuel pressure. To make an injector rated at 19 lbs/hr(at 43.5 psi fp) to flow as much as a 22 lb/hr injector, you would need to increase the fuel pressure to 57 psi! You would think the workaround would be to get an adjustable fuel pressure regulator and just crank up the pressure. Briefly - DON'T DO IT. And don't listen to someone who tells you to do it.

Higher fuel pressure will generally give you better fuel atomization, but it will also increase the work the injector has to do, which will shorten the injector's lifespan. Further, increased fuel pressure will slow down the injector's response time, which in turn increases the injector's duty cycle. At a duty cycle of 85%, the injector will temporarily freeze(flutter), delivering as little as 1/2 the required fuel. Since you are only likely to reach this high a duty cycle during WOT, you would be leaning out the mixture when you can least afford to do so.

As a general rule, you should not increase fuel pressure more than 10 - 15%. After that, you should determine your engine's fuel requirements and switch to a an appropriately larger injector.

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He who hesitates,... is lost!