I have a 1986 iroc lg4, with a 1984 305 block.

i have a weak cylinder #7 so ill be purchasing a set of 081 heads because i am 95% sure it is a burned valve.

Anyway even in the condition of the motor it has really impressed me performance wise. I am head to head with my friends 2000 mitsubishi eclipse GT v6. And i beat my friends jeep grand cherokee with the high output 4.7 rated at 285hp 330torque. Im really blown away by this 5.0 lol


The little 305 performs better than my old 355! i dont know how, but i know this block was worked on at some point. has a weiand stealth intake, shorty headers,holley 4160, and a shift kit.


So i plan on buying a set of 081 heads,get them ported and polished and hopefully stretch its life long enough to work on other areas of my car like paint and suspension.

how well would the 081 heads work after some work? In the future if i decided to swap to a 350 could i use the same heads or would i get too high of a compression on a 350?

When swapping the heads should i use the externals from the 081 heads or my old heads? by externals i mean rockers/pushrods. i dont want to cause pre mature wear.

any info appreciated.

 

Any particular reason for 081 heads? You should have 416 heads now - same thing except for the intake manifold mount bolt angles and valve cover type.

I would certainly verify the reason for the dead cylinder first. A wet/dry compression test should establish that. Or, loosen the rocker arms and put compressed air on the spark plug hole, listen for where the air comes out (intake, exhaust, or crankcase).

 

nope no particular reason, they are just available, i read they are a decent head and with some work can make good power on a 305. are you saying the 081s will use centerbolts? and will i have any fitment issues?

my current heads are perimeter bolt


EDIT: five7 after doing some research i read ill need a different intake or id need to drill holes into my existing ones.

can you recommend me a good intake to run with the 081s and a holley carburator 4160?

 

Why not just rebuild the 416s?

 

cant really afford any downtime so i want to have a set ready to go on as soon as others are off. Thats pretty much the only reason. Thought about vortecs but i dont want to lower the compression on the 305 with bigger chambers. So now i need to look at an intake because i wasnt expecting the 801s to not to be a direct fit

 

081's I assume you mean.

Still say verify you have a valve problem before doing any work on the heads or pulling the engine apart.

 

Putting fresh heads on a engine w/ low compression is a gamble. It might be an oil burner when youre done.

 

Now I know this last post is very true.

 

I have some 187 heads for 50+ shipping I'm bout to scrap them soon