1979 Getting Started

[1987 GMC Jimmy]

A 70s era 305 is indeed a real dog compared to an L69.
L69s have great heads and an additional 1.3 - 1.2? points of compression to work with.
If you wanna play with a smogger 305, consider those factors. The 601 heads have decent chambers and are 53? CC but the intake runners are "meh" at best.

POP some flatter top pistons and change your cam I bet it'll run ya good for awhile. I think you'd be wasting both time and money rebuilding 601 heads, says the guy that just put #416s on his 350 to replace his 426s? 624426?
Whatever..
I used to have an L69 that would KICK THE **** out of a whoooole lotta stuff, i'm a believer in the 305 powwa!

I'd have to show em. Thank god it has 5.0 cast on the block, nobody believed me.

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I agree. I think the L69 redeems the piss poor performance of the other ones more or less excluding the LE9. If you dug into it and did the standard upgrades, it’d definitely make a believer out of some people.

 

[4WDKC]

leave the 305 alone while you get the big block ready, only put money into the 305 for oil changes/tune up/filters

 

[RustyPile]

I agree. I think the L69 redeems the piss poor performance of the other ones more or less excluding the LE9. If you dug into it and did the standard upgrades, it’d definitely make a believer out of some people.

The 305's small bore (3.736) prevented large valves and subsequent large runners.. Even the GM "hot rodders" couldn't crack the 200 HP barrier with a carburetor.. The IROC Camaro and the Trans Am made it to 215 hp with the aid of tuned port fuel injection and 9.6 compression ratio.. The 305 HO was a performance engine in hype and the minds of the GM engineers only.. One of the car magazines (Motor Trend, I think) conducted some road tests of the Camaro and Monte Carlo SS.. The best 1/4 mile performance they found was ETs of 16 point something seconds and MPH of sub 90s.. Later tests of the IROC yielded MPH of around 91 with ETs of around 15.9 or there about..

The only thing a 305 does well is gas mileage..

 

[Russell Jones]

....Rock auto sells gas new tanks for less than $100, at that price it’s not worth messing with trying to clean out an old one

The engine will Probably run ok

A Chevrolet will run poorly longer than most cars run at all

Copy on the rebuild of the brakes. I love that parts for these trucks are so cheap. MUCH different and greatly appreciated compared to the german car market.

Gas tanks...how hard are they to change out?

10mins? 10 hours 10 days?

 

[Rusty Nail]

It's 2 bolts and a pair of hose clamps..

 

[roundhouse]

Two very rusty bolts and three very old hoses

All the hoses will need to be replaced

You can swap out the tank by yourself but it’s a lot easier with a helper and a floor jack
Helpful tip ; drain it first, if you can

 

[CSFJ]

Two very rusty bolts and three very old hoses

All the hoses will need to be replaced

You can swap out the tank by yourself but it’s a lot easier with a helper and a floor jack
Helpful tip ; drain it first, if you can

Or, if you really want to make it easy, pull the bed back out of the way. That way you can attack from above, instead of using your face to catch all the rust/dirt/debris that falls off from underneath.

 

[Rusty Nail]

Lol! using your face ...haha.

 

[Dougnsalem]

I like to yank the driveline. Plug in the tranny so the crap doesn't get everywhere. (Ha ha- that doesn't sound so good....) Sure, its more work, but then I get to sit on my butt, between the two tanks to work on it...

 

[Derrick]

Copy on the rebuild of the brakes. I love that parts for these trucks are so cheap. MUCH different and greatly appreciated compared to the german car market.

Gas tanks...how hard are they to change out?

10mins? 10 hours 10 days?

It should only take 1 hour but you know how it works it will take 3x the time and the best way to attack this if you have only your self is power wash the underside to get the dust mud sand salt snakes dead rodents out then let it dry jack up the truck take a motorcycle jack put it under the gas tank (I say this due to the larger area that the jack touches of the gas tank) let the tank down slow after you take off the lines and screws (you know you did the line removel right if you get gas down you arm and all you smell is gas). Put the new tank in place (I would recommend new hardware and a new sending unit) and your done (before you start the truck next cycle the ignition a few time to get the fuel primed and i would also change the fuel filter while you are messing with the fuel system.

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[Honky Kong jr]

It should only take 1 hour but you know how it works it will take 3x the time and the best way to attack this if you have only your self is power wash the underside to get the dust mud sand salt snakes dead rodents out then let it dry jack up the truck take a motorcycle jack put it under the gas tank (I say this due to the larger area that the jack touches of the gas tank) let the tank down slow after you take off the lines and screws (you know you did the line removel right if you get gas down you arm and all you smell is gas). Put the new tank in place (I would recommend new hardware and a new sending unit) and your done (before you start the truck next cycle the ignition a few time to get the fuel primed and i would also change the fuel filter while you are messing with the fuel system.

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That or take the little round thingy off your jack and attach a piece of 2x12 to your jack. That’s how I dropped mine for disposal.

 

[Russell Jones]

Thanks fellas. I just got off work this morning and off for the next 4 days. I plan to dig into the truck some more..