Post 305 to 350 swap questions
#1
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Location: Tacoma, WA
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Car: 85 Z28 & 86 TA
Engine: 350 Crate Motor & 305 TPI
Transmission: 5-speed & 700R4
Axle/Gears: 3.23 Open End & 3.27 posi
Post 305 to 350 swap questions
Hi,
Re: 85Z28 with non-wc t5 and 3.23 gears, 16 inch wheels 50 series tires
I did a 305 non-ccc (Edelbrock 600)/dizzy 350 non-ccc (Q-jet 750? w/ heat activated choke)/dizzy swap along with headers in February 2014. I've been driving more this summer and have noticed a few things:
Oil pressure reads higher than before.
RPMs seem higher in when in 5th gear, but at least the shifter doesn't "wobble" like it did before when driving 55-65 mph
RPMs seem higher in when in 4th gear...would imagine I should be around 3230 at 70 mph, but looks closer to 3500
Are these things normal or should I be concerned about any of them? It's not a daily driver, so whenever I do drive it, I have to get used to all the things I'm not typically used to. (I'm also hearing a ticking noise, but I'm thinking it may be a sparkplug wire arcing (need correct plugs and wires) or an exhaust leak (need to install the Remflex header and collector gaskets). Any input on this would be helpful. I did search the board, but did not find something that matched my car's set up. Thanks!
Re: 85Z28 with non-wc t5 and 3.23 gears, 16 inch wheels 50 series tires
I did a 305 non-ccc (Edelbrock 600)/dizzy 350 non-ccc (Q-jet 750? w/ heat activated choke)/dizzy swap along with headers in February 2014. I've been driving more this summer and have noticed a few things:
Oil pressure reads higher than before.
RPMs seem higher in when in 5th gear, but at least the shifter doesn't "wobble" like it did before when driving 55-65 mph
RPMs seem higher in when in 4th gear...would imagine I should be around 3230 at 70 mph, but looks closer to 3500
Are these things normal or should I be concerned about any of them? It's not a daily driver, so whenever I do drive it, I have to get used to all the things I'm not typically used to. (I'm also hearing a ticking noise, but I'm thinking it may be a sparkplug wire arcing (need correct plugs and wires) or an exhaust leak (need to install the Remflex header and collector gaskets). Any input on this would be helpful. I did search the board, but did not find something that matched my car's set up. Thanks!
#2
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Re: Post 305 to 350 swap questions
The engine RPM at different gear speeds would not change unless you changed the transmission gear ratios or the rear axle ratio, or perhaps tire size. Regardless of engine displacement, the final drive speed and engine speed are determined by the transmission gear ratio and the axle ratio- picture it like this, one revolution of the clutch will in fourth gear turn the output shaft on the transmission one time (assuming that fourth is a 1:1 ratio) and the tire about a third of a rotation (assuming a 3.08 gear ratio). If I hooked up a 2.0L toyota engine, at 500 rpm the clutch would still turn 500 revs in one minute. The same would be true if I hooked up a 454 and ran it at the same 500 rpm.
If you put in an engine with tighter clearances, the oil pressure will reflect. Oil pressure is a reading of the hydraulic force the pump is having to produce to push oil through the main bearings and cam bearings. If the engine is more worn, meaning the bearings and journals have more clearance between them and the crank and cam, the oil pressure will be lower. If there is less space there, than the oil pressure must go up if the volume remains the same. Hope this helps,
-Berlinetta00
If you put in an engine with tighter clearances, the oil pressure will reflect. Oil pressure is a reading of the hydraulic force the pump is having to produce to push oil through the main bearings and cam bearings. If the engine is more worn, meaning the bearings and journals have more clearance between them and the crank and cam, the oil pressure will be lower. If there is less space there, than the oil pressure must go up if the volume remains the same. Hope this helps,
-Berlinetta00
#3
Re: Post 305 to 350 swap questions
I have a 92 firebird with a 305 tbi and I want to put a carbed 350 in it that I have laying around but will all my gauges work and will I pass inspection
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Join Date: Aug 2014
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Engine: 5.0 tbi
Transmission: 700R4
Axle/Gears: stock
Re: Post 305 to 350 swap questions
im going to swap my tbi L03 305 for a 350. i plan on keeping the tbi and everything else in place. from research on this site it is my understanding i will need to change the knock sensor, fuel injectors, esc module and have a chip burned for the ecu.
all that aside my question is what year of 350 do i look for? what kind of car/truck would have came with the type engine im looking for?
im not looking to use adapters or work arounds. i want to bolt it up and go.
any input is greatly appreciated.
all that aside my question is what year of 350 do i look for? what kind of car/truck would have came with the type engine im looking for?
im not looking to use adapters or work arounds. i want to bolt it up and go.
any input is greatly appreciated.
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