cheap-ish options for my 86

[shortarms]

I have a 1986 K10 suburban (carbed, OE quadrajet). I bought it last year, odometer shows 25xxx miles. I'm guessing based on vehicle condition that it's 125 or 225. Engine is stock, minus most of the smog. I am still running the cat because I haven't had time to yank it off. I'm only running vac advance, booster, hvac, and trans lockup. EGR is blocked. Heat riser/EFE is wired open for now. I've never really done anything performance-wise with GM stuff until now, so these may seem stupid questions. I haven't checked casting numbers, but I'm assuming these are the "80s TRUCK" heads, 75cc chambers.

I'm looking to build a little more power. The truck was rated at 265TQ/165HP. It's got the 700r4 with 3.42 diff gears and 31's which don't help matters because of how low the RPMs are at highway speed. I know that moving to 3.73 or 4.10 gears would be an easy-ish fix, but it's not in the cards right now and would be at the expense of mileage as we're just moving the cruise RPM range around. I do plan on doing long tube headers.

Here's the fun part: the heads need to come off. Head gaskets are puking coolant down the sides of the block and valve guide seals are toast. So I'm kind of thinking if the heads need to come off, how can I best spend $$ to get a little power? Here's what I've been thinking:
1- check valves for leakage. if good, replace seals and bolt them back on. block the exhaust crossover. no further changes.
2- #1, plus an intake. (is there any power difference between a new edelbrock and an older craigslist edelbrock?)
3- snag a new set of (65cc?) heads, rebuild them and swap.
4- as above, plus an intake
5- vortec heads, rebuild them, and obviously an intake.

All I'm getting at is that I don't know where to best gain torque per dollar. Will the gain on vortec heads and an intake be worth the cash? Am I taking a chance the bottom end won't hold up?

 

[mtbadbob]

Blocking the exhaust cross over will probably hurt the performance. There is a science behind cross overs, 2 into 1 exhaust systems on almost every combustion engine made. That is why the engineers install them from the factory. A higher flowing muffler & tailpipe will be more advantageous to you for performance. A different cam will be the best way to buy torque also.

 

[Frankenchevy]

Budget?

 

[75gmck25]

Consider your long term plans:
Your best long term fix would be Vortec or aftermarket aluminum heads with 64cc chambers, and use thin head gaskets. This will get compression up (maybe to 9.2-9.4) into a range where a better cam and intake will be very effective. You are well on your way to a very tractable 325-350 hp build, depending on the cam you choose (stay mild duration with a vehicle this heavy).

However, new heads will cost about $800-1000, and after you buy gaskets and other parts it will be at least another $100-200. If you use Vortec heads you will also need a new intake because of the bolt pattern. It’s a great starting point, but quite a bit of money up front.

Rebuilt iron Vortecs will save money, but look for truck heads (062 casting is supposed to be a little more durable) and make sure they are checked for cracks.

 

[shortarms]

Blocking the exhaust cross over will probably hurt the performance. There is a science behind cross overs, 2 into 1 exhaust systems on almost every combustion engine made. That is why the engineers install them from the factory. A higher flowing muffler & tailpipe will be more advantageous to you for performance. A different cam will be the best way to buy torque also.

I was referring to the crossover in the intake manifold, sorry for the confusion.

 

[shortarms]

Consider your long term plans:
Your best long term fix would be Vortec or aftermarket aluminum heads with 64cc chambers, and use thin head gaskets. This will get compression up (maybe to 9.2-9.4) into a range where a better cam and intake will be very effective. You are well on your way to a very tractable 325-350 hp build, depending on the cam you choose (stay mild duration with a vehicle this heavy).

However, new heads will cost about $800-1000, and after you buy gaskets and other parts it will be at least another $100-200. If you use Vortec heads you will also need a new intake because of the bolt pattern. It’s a great starting point, but quite a bit of money up front.

Rebuilt iron Vortecs will save money, but look for truck heads (062 casting is supposed to be a little more durable) and make sure they are checked for cracks.

That's kind of my thinking, but I'm not looking to touch the cam right now. Definitely not looking at new heads either, I should be able to pick up a set of core stock vortecs for $100-$200 and then get them rebuilt. Since I have to pull the existing heads anyway to resolve the coolant leak, gaskets are almost a moot point. I know I'd have to change the intake manifold but again that's inline with "if the performance bump is worth the $$".

Is there any truth to the 906 vs 062 casting issue thing, or just an old wives tale? I've only recently heard about it.

 

[shortarms]

Budget?

Budget is low but variable. I know that I can just R+R everything and keep it cheap, but I'll have zero gains. I'm not upgrading the cam at this point. Everything else is fluid based on what seems to make the most sense.

 

[CheemsK1500]

The truck should have a 305 in it, unless it was swapped at some point. I'd just run it as is, save money and find a 5.7 Vortec, and run a carbed intake on it, unless you wish to do a TBI conversion.

A lot of people suggest an LS swap, those are great engines, but they won't drop in and bolt up like the 5.7 Vortec will.

 

[75gmck25]

The Vortec 062 vs 906 head debate is a little like debating what weight of oil to run. There is a lot of good and bad info out there. I think the key is a good rebuilder and a full check for cracks.

062s were supposedly used on 3/4 ton trucks, which kind of implies they are a little more durable. However, I don’t know enough to verify anything.

 

[shortarms]

The truck should have a 305 in it, unless it was swapped at some point. I'd just run it as is, save money and find a 5.7 Vortec, and run a carbed intake on it, unless you wish to do a TBI conversion.

A lot of people suggest an LS swap, those are great engines, but they won't drop in and bolt up like the 5.7 Vortec will.

No, RPO is LS9. It's also a non-ESC distributor, straight HEI.

I'm not LS-swapping (or any FI for that matter), for reasons I don't want to get into. I'm in the air on swapping the carb though.

 

[CheemsK1500]

No, RPO is LS9. It's also a non-ESC distributor, straight HEI.

I'm not LS-swapping (or any FI for that matter), for reasons I don't want to get into. I'm in the air on swapping the carb though.

Looks like you lucked out on the engine. Most 1/2 tons I find have the 305. Since you already have the 350 to start with, perhaps you could look into Vortec heads and play around with different intake and carb combos.

 

[Ricko1966]

Just find a running 96-99 vortech in the bone yard. Now you've got your heads and a roller block all in one,and it will bolt right in.You can't do aftermarket retro roller for what you can buy an engine out if an Escalade etc. at pik n pull. Find one that's the boned or hit a deer and you know it's a driver. Seriously when I'm looking for bone yard stuff I try to figure out why it's there.perfect body,clean interior,the columns not broken. It doesn't run and was towed from an apt. complex parking lot. K.C. Pik n Pull, long block Including core 225.00 there's your big bang for the buck a cam and a manifold and you have about all you can get for cheap power wise.