I've been reading the posts these past few days, and so far I'm seeing people being against dropping a 305/350 into a v6 car. What about dropping a 350 into a 305 equipped car? I'm thinking the weight difference won't be so much, but also will the tranny/rear end be able to handle it?

It's a 700R4 that I plan on installing a 2500-2700 stall on (would it need a shift kit?) The engine will be installed w/ an MSD super HEI kit and Edelbrock TES headers. The rear end is a 3.23 factory posi.

Plus, the car only has 87k miles on it now (I see people have 305's w/ over 100k miles, and they swap for a 350, but the tranny and drivetrain will still have over 100k miles on them.)

My dad's telling me for the amount of money I'd spend on the swap, to just find another 3rd gen w/ a 350 in it already. But I'm thinking I'd rather start from scratch, as I'll know what shape the car is in, that the engine has 0 miles on it, instead of just buying someone else's headache. Sorry for the long post and thanks in advance for any advice. (btw... I'm a senior in high school on a ~$2000-$3000 budget but can do all labor myself w/ my dad.)

[This message has been edited by Chevy83Z28 (edited November 30, 2001).]

 

350 into a 305 car is the best swap there is.
Almost everthing is common to both engines.
Check the Posts.

------------------
1987 Black Camaro IROC-Z (original owner) Replaced LB9 @ 86100 miles.
New 350 Crate engine
Balanced & blueprinted
World Prod SR 67cc Heads 9.6:1 C.R.
Cam: 454lift,216dur@50,110ls
TPI Induction(from 305)
22# Fuel Injectors
AFPR & Gauge
SLP Intake runners
Fastchip stage 2 chip
K&N filters & Air Foil
Hothkis STB
SLP 1 3/4 Headers
CATCO 3" Catalytic conv.
SLP 3" Cat Back Exhaust
700R4 Auto
SLP Torque Converter (2400 stall)
1LE Aluminum Dr Shaft
B-W 9 bolt rear 2:77 Possi. Four wheel disc brakes,245/45/ZR-17 Tires
17x8.5 ATI 5 Razze Wheels
Dyno results: 211 RWHP & 282 RWTQ.
271 HP & 362#/ft at flywheel with all Emission controls installed. New Toy!

 

I hope your budgeted amount doesn't include having to buy the car as well. If so, your dad is right.

GM actually came out with a kit to upgrade a 305 carbed car with a ZZ4 350. They included upgrade parts for the tranny (kind of a "shift kit light") and upgraded lower control arms for the rear, but not a higher stalling torque converter. That should answer some of your questions, although I would recommend the converter anyway. Also, just so you know, there are no differences in strength between V6 10-bolt rears and 305 or 350 10-bolt rears.

A 350 with aluminum heads (what the ZZ4 has) will weigh less than a 305. Otherwise, they will weigh basically the same.

I'll second Z28D, the 350 is a good swap.


BUT, you can be happy with an improved 305 as well. What I've done is certainly within your budget as long as you supply the labor. And, if you don't upgrade the exhaust as part of your 350 swap, wanna run me? I always enjoy an easy win...

BUT #2: If you need to overhaul your 305 shortblock (bore it out, new pistons/rings, turn the crank, etc.), don't bother. Spend your money on a 350 instead.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4, 2300 stall TC. Ported World 305 heads, Crane PowerMax 2050 cam. ZZ3/4 intake, oil pump, pan & baffle. Accel HEI SuperCoil & module. Hooker 2055 headers, 3" Catco cat & 3" catback w/dual-opposite Flowmaster 80. 2.93 limited slip. Spohn SFCs waiting to be installed. AMSOIL syn lubes bumper-to-bumper. Daily year-round driver. Best ET, speed TBD...
57 Bel Air, my 1st car. '66 396, 9.7:1 forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 700 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

Thanks for the replies guys. I already have an 83 Z28 w/ the LG4, so buying the car is not included in the budget.

I thought of modding the 305, and I spoke to my dad about it, and we decided that since the engine already has 87,000 miles on it, to put on new heads and cam and all is risky. I have no idea what shape the rings are in, and my dad said that by raising the compression in each cylinder may blow the rings, which would make all the work and effort to the 305 a waste.

To go cheap, could I buy the 350ho (bare) and use the 305's intake manifold and all? I wanna get rid of the computer (which means prolly new carb/distributor (carb is computer controlled.) And I've read that the torque converter lockup is also computer controlled. But if I were to buy a higher stall converter, would the new one also be computer controlled or can I get a non-computer controlled one that will still have the lock-up function?

 

My LG4 had 143,600 miles on it when I did the mods in my sig. It did not "blow" the rings. Those little ol' 305's are actually pretty tuff.

Your '83 LG4, however, will have dished pistons. So, the gains from performances mods would be reduced. The 350 is a reasonable choice in your situation.

People are probably getting sick of hearing me say it, but I would not recommend converting from computer controls to mechanical for a street driven car. If you have emissions testing/inspection, it's not even a consideration. But, driveability and economy will surely suffer if you go to a non-CC system from a CC system that's working properly. The articles "Stroke in the Desert" on the magazine section of the board is a case in point, and I'll put myself on display as another.

That said, I wouldn't recommend the 350 HO, because it will not be as easy to do and maintain the CC controls. I have plenty of gripes about Vortec heads as well - I can expound if you'd like. For one thing, your current 305 intake manifold will NOT fit!

As for the torque converter, again look at my sig. It has the lockup clutch in it, as do many other aftermarket higher-stall converters available. Keeping the CC controls will make that one more thing that you don't have to mess with.

 

Thanks for the replies everyone. I'm gonna look further into going cc or non-cc, but my main question about the torque converter was not if it would have a lock-up, but if I'd have to use the computer to control it, or if the new converter wouldn't need the computer.