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View Full Version : picking the motor for my IROC...


V
01-25-2006, 04:27 PM
In a few weeks I'm gonna start working on my 1985 Iroc-Z, the motor is tired and at least needs a rebuild. So now i have several choices as to motor selections, here they are...

1. stock rebuild of current 305
2. rering a 350 i have already (bored .040" over)
3. 91 305(7k miles on previous rebuild)
4. '87 305 i have from a previous vehicle (ran great)
5. 383 stroker(rering and new cam would be needed)

on top of that, i need to decide if i want to re-use the elec. quadrajet and oem distributor or if i'll just go regular carb and new dist.
if i chose the 383, i need to find an exteranly balanced 153t flywheel for a 2 piece rear main seal(i have yet to find one anywhere) The car is a 5spd, with factory 3.73 gears, flowmaster catback, and ttops. I want it as a cruiser, I dont care if its that fast and i prefer it to be somewhat fuel efficient(i wont go tpi or such though) I have other plans for this car that will make it stick out. I may do subframes.

As of now im leaning towards the '91 or '87 305(i'll just need to buy a 153t 1 piece RMS flywheel) and i'll switch to a holley carb and a MSD pro billet distributor w/ blaster coil and 6A ignition box(i have all those ignition parts already), id also be using edelbrock TES headers i have layign around.

Whats everyone think?

enRo
01-25-2006, 04:50 PM
Good choice. Id say just whip up a nice cruiser. I wouldnt go all out on it if you dont plan on doing something positive with it as in racing, show, etc. The GrandMother SBC aka 305 should fit in there quite well

NJSPEEDER
01-25-2006, 05:17 PM
that 383 wouldn't be the wrong answer in any car.

The Fixer
01-25-2006, 05:40 PM
Paul, I have a nice cammed 305 that'll be available pretty soon. :)

Tru2Chevy
01-25-2006, 07:16 PM
I was gonna suggest that you toss a mild cam into one of those 305s and call it a day, but Steve may have your solution for you :)

- Justin

camaroAL
01-25-2006, 11:40 PM
i have a flywheel used, and a new pioneer balancer for a 383, $50 its yours

Rich189
01-27-2006, 03:20 AM
personally id go for the 383 stroker.... just for the simple fact that if i rebuilt one of the 305's then id eventually regret not having gone for the 383.... but if its just gonna be a cruiser and you know you wont have the desire to go faster with it then the 305 is more practical i guess

V
01-27-2006, 04:23 AM
im pretty sure im gonna go with the 305, im gonna keep the 383 for some future project, considering these are all motors i currently have in my garage, lol. besides if i want more hp, i am already planning my motor build for my SS as well, a blown 422 stroker.

Rich189
01-27-2006, 01:23 PM
im pretty sure im gonna go with the 305, im gonna keep the 383 for some future project, considering these are all motors i currently have in my garage, lol. besides if i want more hp, i am already planning my motor build for my SS as well, a blown 422 stroker.

:drool: wish i could afford to mess up my bumper to bumper and had the money to do what i wanted with my motor

Oddball
01-30-2006, 08:58 PM
Depends on your use for it. My 86 IROC is a "daily driver" sunny day cruiser so the riginal 305-T5 is great. Drop in the 350 383 in your car and you may need to upgrade the tranny, rear end, brakes, etc... If you just want a nice cruiser any of the 305's will work well.

V
01-31-2006, 01:13 AM
yeah it'll just be a basic cruiser/show car. I got it for free from my friend when he joined the army, and i wanna be able to drive it without worrying about performance upgardes and all. besides, i'll eventually have my '79 vette and SS to go fast in. and i also found out 85 iroc with the 305 L69 and T-5s were like the only 3rd gens to get stock 3.73 gears. at least thats what some site said a the list of production numbers, models, options etc.

IROCZBeast
02-07-2006, 06:19 PM
yeah it'll just be a basic cruiser/show car. I got it for free from my friend when he joined the army, and i wanna be able to drive it without worrying about performance upgardes and all. besides, i'll eventually have my '79 vette and SS to go fast in. and i also found out 85 iroc with the 305 L69 and T-5s were like the only 3rd gens to get stock 3.73 gears. at least thats what some site said a the list of production numbers, models, options etc.

If I remember right all L-69's with T-5's came with 3.73's and four wheel disk brakes standard.

I think that began in 83 or 84 and lasted till 86.

SkinnerSP
02-09-2006, 09:47 AM
Do the 350 re-ring w/ vortec heads and a comp x-energy 268h cam, crane race gold 1.6 rr's 10.25:1 cr. it'll be a hard runner, i promise.

V
02-09-2006, 01:17 PM
I'm not interested in modding the motor, i just want a basic cruiser that gets decent gas mileage, I have other cars for being fast.

WayFast84
02-09-2006, 05:20 PM
I think the 305 is a great choice! plus with a 350 or 383 I think the t5 would go boom...

Oddball
02-09-2006, 05:48 PM
I think the 305 is a great choice! plus with a 350 or 383 I think the t5 would go boom...

LG4

LG4

LG4

WayFast84
02-09-2006, 07:25 PM
LG4

LG4

LG4
:twisted: I like the way you think! :twisted:

V
02-09-2006, 08:56 PM
actually, stock motor is an L69

and i ran the 383 in front of a T5 without serious issues, and the 350tpi motor is also paired with a T5. People say they wont last, but so far no problems, and its not like you must beat on a car everyday, drive normally and itll last.

Savage_Messiah
02-10-2006, 02:52 AM
you KNOW you want that 383 back in a car....