Author Topic: '86 305ci mods  (Read 4551 times)

Offline 86SilveradoEric

  • Newbie
  • Posts: 61
'86 305ci mods
« on: February 26, 2003, 02:26:00 PM »
I have a stock 305 in my 86, with only 97K miles on it.  Never been under serious stress like towing; just used for everday driving.  I'm sure the block is still good, and I can't afford a new crate engine at the moment, so I'm curious if there are any good modifications I could do to a 305 to get a little more kick out of it.  It has a great smooth idle, but poor throttle response and lack of power.  Any suggestions?  


Offline 79SilveradoK30

  • Newbie
  • Posts: 53
.
« Reply #1 on: February 26, 2003, 04:59:00 PM »
Definetly get an Edelbrock Performer or Performer RPM intake (depending on the requirements), they're a nice step up from stock and I hear they improve throttle response nicely. Also, try a set of headers (about 1 1/2" to 1 5/8" primaries with 2 1/2" collectors) and an exhaust system.


Offline 86SilveradoEric

  • Newbie
  • Posts: 61
Re: .
« Reply #2 on: February 28, 2003, 11:44:00 AM »
thank you, sir, for the suggesstion...i have looked into that, and it fits my budget, so i'm sure that'll be a route i take..


Offline phaon1

  • Newbie
  • Posts: 29
Re: .
« Reply #3 on: February 28, 2003, 12:10:00 PM »
I don't know what the emmissions requirements are where you live, but you should also look at doing something with your carb too.  Most old q-jets run pretty poorly, so at least a rebuild and a very detailed tuning should help you take advantage of that new intake.  If you can get buy with it, a non-emmissions carb of any kind should help with the throttle responce.

Chris

1981 GMC K10 75K miles on original parts (what few are left)
Exterior Mods
- Royal Blue chameleon paint
- 15X11 Craiger chrome wheels
Interior Mods
- B&M Light Truck Mega Shifter
- Grant steering wheel
- 6 Auto Meter Ultra Light gauges in dash, 2 on a-pillar
- Keyless entry
- Billet dash and door trim
- Solid headboard with four built in speakers
- Sony Mobil ES CD Deck, MTX truck boxes, Jensen AMP
Drivetrain Mods
- GM Racing ZZ4 Engine with H.O.T. Cam kit, 150 amp alternator, PeteJackson Gear Drive
- Hooker SS headers, 2 1/2" SS exhaust, Dr. Gas x-pipe, Flowmaster 2 chamber mufflers
- K&N X-Stream lid and 14" air cleaner.
- Coan 3000RPM custom built torque converter
- Built-up 700R4 transmission
- Yukon 4.11 gears with titanium pins in stock 10 bolt front and 12 bolt rear.
- Eaton heavy duty locker.


Offline bored and stroked

  • Newbie
  • Posts: 59
.
« Reply #4 on: February 28, 2003, 12:35:00 PM »
Ok there are sevral things to consider. 1: 305's stink for power production. 2: 305's are known to eat stock cams around 100,000miles.

So with this in mind, heres what Id do: Cam swap. Get a new comp cams XE262 [or one step SMALLER] Next a intake. If you dont need emissions, get the RPM. If emissions are needed, your only choice is the performer. Next, get the Qjet fully re-built by someone like the carb shop. Finally get some 1 5/8" primary into 2.5" collector headers.

ALL of these things will transplant to the new 350-383 your going to BUILD [not buy] A 350 is simple, a 383 just a tad harder but so easy theres no reason not to do it. Crate engines cost more and give you less for your money.


Offline 86SilveradoEric

  • Newbie
  • Posts: 61
Re: 86 305ci mods
« Reply #5 on: March 03, 2003, 02:11:00 PM »
i was just curious as to how lumpy that compcams XE262 cam is, and will anything in the cylinder heads need to be checked or replaced?  i.e., valve springs, rocker arms, push rods, etc..and another question: my rearend is a stock 10-bolt 2.73.  would installing another rearend, like a 3.73 improve performance of what i have now?  and would adding that to the cam, intake, and retuned q-jet be better than keep the stock rearend?

Edited by: 86SilveradoEric at: 3/3/03 3:19:10 pm

Offline bored and stroked

  • Newbie
  • Posts: 59
.
« Reply #6 on: March 03, 2003, 02:36:00 PM »
Going to say a 3.42 rear would be a HUGE improvement and not kill your engine on the freeway too bad. The xe262 in a 305 would be a little lumpy. I think the nest step down [xe256]is a better idea if no 350+cid engine swap is coming soon. A new set of valvesprings could never hurt, and $60 a set aint bad for springs good to .525" lift [LT1 valvesprings from a 93-97 camaro]


Offline 84 silverado

  • Newbie
  • Posts: 77
more 305 shtuff
« Reply #7 on: March 03, 2003, 08:11:00 PM »
I'd even consider the comp cams/cam dynamics 266 energizer for that little motor. it's got specs of 440/266 and it sounded OK in my last 305 beater(after the factory cam went flat anything sounded good) motor and didn't need alot of spring or special stuff to run it. Keep it cheap, keep it simple and the 305 will run better....... I said better, not good!!!!!


Offline 84 silverado

  • Newbie
  • Posts: 77
oops.....
« Reply #8 on: March 03, 2003, 08:13:00 PM »
sorry guys, I said "comp cams/cam dynamics", when I meant to say "crane cams/cam dynamics". Sorry to all you comp cams lovers out there(myself included) :rolleyes  


Offline Kazz

  • Newbie
  • Posts: 12
Re: oops.....
« Reply #9 on: March 04, 2003, 12:21:00 AM »
I've seen decent results with the Performer cam and intake manifold. I really think headers or at least a very good free flow exhaust system makes a big difference. The 305 can be a little torque monster with decent gas mileage if the right add-ons are installed.

Kazz


Offline bored and stroked

  • Newbie
  • Posts: 59
.
« Reply #10 on: March 04, 2003, 02:37:00 PM »
Run away from edelbrock cams!!! THEY STINK!!!!
Sure they are better then stock, anything is. But there are much better grinds out there with the same basic specs.  

After some debate on another board, the conclusion is that comp XE series cams are not good for daily drivers. Their ramp rates are just too high and they will not make 100,000+mile cams. They are great for power, bad for durability. Stick with somthing other then a XE series cam for daily drivers :)  


Offline 83CHEVY

  • Registered Users
  • *
  • Posts: 134
Get up and Go!
« Reply #11 on: March 04, 2003, 04:52:00 PM »
Your gearing is taking the whiz out of your motor.  If you changed to 3.73's you would think you put a supercharger under the hood.

I have a stock 305 with 110,000 miles on it and 3.73 gears.  It is no hot rod, but it goes pretty darn good.  The only mods I have made are an Edelbrock 1904 Q-Jet (which I love), a K&N filter and an aftermarket distributor.  Other than that, it is just tuned up nicely and properly maintained.

My Dad has a 88 GMC Jimmy with a TBI 350.  My truck will run side by side with his from the stop lights all day long.

Mike

Edited by: 83CHEVY  at: 3/4/03 5:53:45 pm