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305, 350 opinions

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Old Oct 28, 2009 | 12:59 PM
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305, 350 opinions

I have an 86 and an 87 camaro, both have a 305 the 86 is a parts car. The 87 needs an engine rebuild really bad. So I have been debating whether to rebuild the 305 or get a 350 to rebuild. I am a senior in high school and don't have alot of cash lying around. I don't want to get crazy with it, just want a decent engine. I was wondering what some of your guys opinions were
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Old Oct 28, 2009 | 02:32 PM
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
What is wrong with the engine that requires rebuilding?

Rebuilding a 305 is rarely money well spent, regardless of how much or how little you have to spend.
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Old Oct 28, 2009 | 02:35 PM
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From: CO
Car: 1988 rs
Engine: 555BBC; Dart, Lunati, SRP, Howards
Transmission: ATI TH-400
Axle/Gears: 35 spline 9", locker, 3.00's
Re: 305, 350 opinions

Originally Posted by topher1316
I have an 86 and an 87 camaro, both have a 305 the 86 is a parts car. The 87 needs an engine rebuild really bad. So I have been debating whether to rebuild the 305 or get a 350 to rebuild. I am a senior in high school and don't have alot of cash lying around. I don't want to get crazy with it, just want a decent engine. I was wondering what some of your guys opinions were

Definitely rebuild a 350, you could even find 350 short blocks on craigslist. The 305 isn't worth your time. all you accessory pulleys will bolt right up to the 350.
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Old Oct 28, 2009 | 03:52 PM
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Re: 305, 350 opinions

Well the rod bearings are shot, and the rods are pretty much toast too. So if I get a 350 short block, what exactly will or should I keep to bolt onto the 350 from the 305.
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Old Oct 28, 2009 | 04:21 PM
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From: greenfield indiana
Car: 86' IROC-Z....and 5 other 3rdgens
Engine: 383 hsr
Transmission: built 700r4
Axle/Gears: stock 3.23, 10bolt
Re: 305, 350 opinions

guess this depends on how deep your pockets are. once you go 350 (assumming your keeping fuel inj) you gotta get the ecm for it or tune it (which is pricey) and the money that it cost to rebuild the 305, may not be enough to buy a 350 in any "better" shape than the 305 currrently is in. and you also said you didnt wanna go crazy with an engine too, so it sounds like a money situation, so i think itd be cheaper to rebuild the 305.
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Old Oct 29, 2009 | 02:47 PM
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Originally Posted by topher1316
Well the rod bearings are shot, and the rods are pretty much toast too.
What's wrong with the rods, and how do you know that?

Originally Posted by topher1316
So if I get a 350 short block, what exactly will or should I keep to bolt onto the 350 from the 305.
Everything else (but see below).

Originally Posted by cIaRmOaCrZo
guess this depends on how deep your pockets are. once you go 350 (assumming your keeping fuel inj) you gotta get the ecm for it or tune it (which is pricey) and the money that it cost to rebuild the 305, may not be enough to buy a 350 in any "better" shape than the 305 currrently is in. and you also said you didnt wanna go crazy with an engine too, so it sounds like a money situation, so i think itd be cheaper to rebuild the 305.
Depends upon the induction system, and only mildly so. A carb ECM won't care whether it's a 305 or a 350. An '87 TPI just barely cares, as it will run without issues, but a 350 tune would run slightly better. Either should have the knock sensor and module replaced with 350 units.

It would only be cheaper to rebuild the 305 if you paid too much for the 350.
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Old Oct 29, 2009 | 07:31 PM
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Re: 305, 350 opinions

So what your saying is if I get a 350, I don't need a new ecm, but it would be better. But I do need a now knock sensor
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Old Oct 29, 2009 | 11:40 PM
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From: Oregon
Car: 91 Camaro RS
Engine: L03
Transmission: 700R4
Axle/Gears: stock...
Re: 305, 350 opinions

Stay away from the 305 unless you got serious cash. A fun motor but an expensive one. My personal advice.. get an LM7 get some headers and a good tune on it and away you go. The LM7 is the 5.3 liter 325 ci baby brother to the LQ4 6 liter 364 ci out of the silverado. You could always save the 305 for a later build.. i dunno a dune buggy or sn s10 would be good canidates.
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Old Oct 30, 2009 | 01:59 PM
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
The LM7 is an LSx swap. While you might be able to buy a pull-out fairly cheap, getting it installed in a 3rd gen is a different matter. Hardly a high-school-student-budget project.

The '87 TPI system is mass air flow, which isn't as sensitive to displacement changes as the speed density (MAP) systems ('90-'92 TPI, and TBI). The factory used slightly different tuning for 350 vs 305 MAF, but no so different that a 350 won't run with 305 tuning. Howver, the knock sensor is sensitive to displacement (bore size, reportedly), so change that to 350 parts.
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Old Oct 30, 2009 | 08:07 PM
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From: Oregon
Car: 91 Camaro RS
Engine: L03
Transmission: 700R4
Axle/Gears: stock...
Re: 305, 350 opinions

[quote=five7kid;4331106]The LM7 is an LSx swap. While you might be able to buy a pull-out fairly cheap, getting it installed in a 3rd gen is a different matter. Hardly a high-school-student-budget project.



ah ha, yes... words of wisdom. i did not take that in to account. my bad!
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