New Member with Engine Swap

[sunrunner]

Hi All, New Member, Brandon / 30 / Louisiana

I am fixing to do a 350 swap on my '84 2500 HD because I looked into rebuilding it and found I could replace it cheaper than I wanted to rebuild it, and will get an amazing warranty on the swap motor.

I work at an Advance Auto Parts so the sky is the limit as far as options go. My plans so far include a rebuilt 350 with 150,000 mile warranty, MSD 6AL ignition, Edelbrock Torker II intake with Holley Street Avenger II 850 cfm carb, Dynomax Headers, Geared Timing, and an Autometer Instrument Cluster.

As soon as the warranty is up on the block, I plan on replacing the stock heads with some nice new Edelbrock or Holley competition heads, a new Stall Converter and a shift kit on the old TH 400, and a good cam with a lot of lope. I'm even thinking of stroking the rebuilt 350, but that's only on the drawing board right now.

Couple quick questions:

I hear people mention replacing the V-Belt setup with a new serpentine belt system, but I can't find any information on who makes a replacement kit, obviously AAP doesn't sell one, or I'd already own it. Who makes a V to Serp replacement pulley system?

And the other one, I know I'm going to attempt to sqeeze every last horse out of the 350 once the warranty is up, but I am going to want to cruise around in it as well, and on pump gas definately. Where does it stop? What's the limit I could push it to on horsepower / street use without getting away from pump gas? I know nascar can push these things to 750 horses and right up to the 9500s on revs but you couldn't even crank them on 92 octane. Recon motors will take the 350 and bore / stroke it to close to 430 c.i.d. and squeeze 520 hp and 575 lb/ft torque out of it with a 75,000 mile warranty for right at $3000, but without boring it, what can I do?

Thanks Guys,

Brandon

[MylilBowTie]

Welcome to the fourm!

[Ron 586]

Welcome to the board from West Tennessee. Good luck with your hot rod 2500. Post a few pictures when you get a chance.

[Tx Firefighter]

A real good way to swap to serpentine belt system is to rob parts off a later model truck or Suburban in a junkyard. Look at late 80's, early 90's vintage. You can even use a setup off of a 4.3 V6 engine on your 350.

[Hoods69BadBowTie]

Sounds like your headed in the right direction. I was also going to suggest checking around at the junkyards to find a newer truck with the serpitine setup.
I would go ahead and bore the motor out once your warranty is up.
-Later

[84slopwaggin]

Is this your main daily driver or what? If so you need to rethink your setup you have planned. Alot of stuff you listed would do great as drag step, but not as well on the streets. I would never compare a street car to a Nascar.

[Slonaker]

Consider a new 350 instead of a rebuilt one. Mine was $1359 + $100 shipping from www.summitracing.com.

Slonaker

[MylilBowTie]

I wouldn't put to much faith in any engine from Autozone or Advance auto parts. They have a horrible track record for being not so good. I would go the gm universal 350 that I believe Slonaker was talking about. Much better quality vs used cores and mix matched parts.

I wouldn't worry about getting the engine bored out bigger for performance sake its not worth the benefit of a few horsepower.

If you really set on those kind of horsepower numbers look for a big block. It will cost more up front but less than it would to build up a small block like you want.

[gchemist]

Use the serpentine belt system from a 94-95 pickup. v6 or v8 work. The brackets don't have provisions for a smog pump. Bolt right in too.

[sunrunner]

Well, after a bit more reading and asking a few commercial customers who buy our motors regularly, the reman 350 we sell for $1150 isn't so bad, but it is definately not a powerhouse.

As of right now, I have the top end and front end of the motor off, one of the cylinder heads off and am going to pull off the other cylinder head today. If I get a spurt of energy I may even yank the block out of the truck today. I'm still looking into a good performance setup for daily use and have revised my setup somewhat.

I have decided to rebuild it myself, I bought it knowing that it was a rebuilt motor and after seeing the pistons I know that the guy did it himself and on the cheap. Looks like some of those $12 hyperwhatever aluminum dual cupped pistons. They actually look to be in good shape but I think I'll just yank them and go with some better ones anyway.

How can I tell if the motor has been bored over stock, can I just measure diameter of the pistons with a caliper? Or is there some fancy neat little thingie I need to purchase to run the inner diameter of the cylinder walls? ( Can you tell this is my first rebuild?)

I'm going to start hunting down junkyards in the near future, as I'm in southwest louisiana, the sky is the limit for junkyards, I can't drive 5 miles down the road without seeing at least one or two of them, I think I'll start hunting down some matching bucket seats out of a Jimmy/ Blazer or a Suburban to replace the old junk bench it has, I'll also be keeping my eyes open for a 88-97 model truck to scavenge the pulley system and brackets off of. A commercial customer of mine mentioned hunting down some 96-99 350 Vortec Cylinder Heads for a nice 50-70 hp gain over stock right off the get go, and that prompted some research and I found that I can scavenge the vortec heads out of a junkyard too and rebuild them with the valvetrain from the 79-87 setup without having to mod the cam for proper valve lift clearance. That's a major plus in my favor.

Since I'm going to be rebuilding it myself, the heck with it, I'm gonna stroke it. So, here's what I'm gonna end up with:
Original 350 block stroked to 383
Vortec 350 Cylinder Heads rebuilt with 79-87 Lunati Performance valvetrain
Melling Hi Volume Oil Pump
Aftermarket Oil pan with 9 quart capacity
Somewhat *wild* cam (haven't researched it yet) (open to suggestions)
Full MSD Ignition setup with Distrib, Coil, and 6AL controller
Edelbrock Vortec Air-Gap RPM Intake with a 2" Riser
Holley Street Avenger II 850CFM carb with electric choke
Holley Performance Mechanical Fuel Pump
Dynomax Ceramic Coated Headers back to true dual 2.5" exhaust
TH400 Auto with shift kit and 2500 stall converter
Autometer Ultralite II Instrument Cluster with 5" Speedo and Tach
Lunati Performance Timing Gears

I've already started collecting the aftermarket stuff, got the Carb, Headers, Fuel Pump, some of the gauges, an aftermarket cam I don't have the first clue about, and the dual exhaust piping and mufflers. She's going to be a sleeper, trying to keep the exterior in original condition. I'll paint her when I'm done, she's two tone blue top / grey bottom now, I'll probably go with a metallic blue flake or gloss white and whichever I use as my primary, I'll put twin 18" stripes right over the middle of the hood and cab in the other color. She's sitting on 16" x 8" eight lug white wagon wheels now (scavenged off a ford diesel)with some 235/75R16 10 ply Michelin Loadmaster tires. I'll probably pull them off and repaint them and put them right back on, they look good and plain (sleeper, remember). I have some Thrush Mufflers to keep her quiet at idle, they sound odd (only way I can describe it) but they don't restrict the flow much and they are definitely quiet when she's sitting still.

Now I just have to figure out a good rear end for highway driving, ideally I'd like a 0-60 in 3-5 seconds and running at 70-80 on the highway at around 1800 rpms, at least that's what I'll be shooting for. With that much displacement I will guestimate high 300's to low 400's Hp and middle 400's torque and that's pretty much what I am aiming for. Now I'll probably have to research the best way to connect that to the rear wheels.

I haven't the first clue where the rear end is geared, being a 2500 series truck, with a stock rear end I'd imagine it'd be in the middle of the 3's for pulling and hauling, right? Or would that be the 3500 series? One of these days I'll lift the rear end off the ground and scribe and spin it to find out, probably today since I'm thinking about it.

So, this is a nice and long winded post, but it sums it up nicely, I'm down to research on two topics, a good cam and a rear end that'll put me just under 2000 revs on the highway at cruising speed.

-SunRunner-

[Slonaker]

I think you will have a hard time keeping the RPM at 1800 at 70 or 80 mph without an overdrive. To do it, I suspect you would need some really tall gears that would make it accelerate poorly. You could go with an overdrive transmission or add a gearvendors overdrive unit (expensive) to reach your goals.

The Suburban/Blazer seats won't just bolt in. You will have to fabricate mounts to make them fit due to differences in the shape od the floor. The gas tanks in your truck are mounted under the cab, which gives the floor the different a different shape.

Slonaker

EDIT: Before you spend any money on that block, make sure it is a 350. I have heard too many horror stories about people who think they have a 350 and it turns out to be a 305, 307, 283, or whatever. It happened to my dad a few years ago.

The number is on the back of the block, behind the valve cover. You can look it up on www.mortec.com to find out what engine it is. A 350, I believe, should have a 4 inch bore. If a quickie measurement with a tape measure is not approximately 4 inches (since you have a head off) you might want to make sure it is a block you want to spend money on.

[MylilBowTie]

Yeah a 350 is a 4.00 inch standard bore. You can usually tell if its bored by looking at the piston top it will have .020-.030 something like that sometimes.

850cfm carb is a bit over kill for a small block that is getting driven on the street. I would go with a 600-650 re-jetted to your engine. Only thing bigger cfm size will get you is more rpm and way more fuel. Being you want to go with a stroker motor its not made to rev high like a 327 or 302. With a 650 its good to 6500 rpm and that's pretty high for a stroker. That 850 would handle 10000 rpm the 383 its a little of kill. Driving it on the street would really suck some gas and throttle response wouldn't be as good.

You are going good with a 383. The 3/4 is heavy so you will need a lot of torque to get it moving. Especially if you want to get low 0-60. That is a lot of weight to just get up and moving. I have 3.42 gears in my 86 3/4 ton but its kind of hard to say what yours has. Good idea would be something like 3.42 - 3.73 - 4.10 just depends.

[sunrunner]

Yeah, I realized after I posted that 1800 at cruising speed is somewhat unrealistic, I should be shooting for 2200-2500 at cruising to where the stall converter is right at the edge of flashing into lockup. Looks like the rear end is set somewhere around 3.70ish from scribing and spinning it.

Engine is definately a 350, we have a disassembled 305 in the store by the entrance and just by looking I know mine has bigger pistons, and according to the marking on the block it's a GM Goodwrench 350 and matches the vin on the vehicle, so it's the original block, pistons are so coated with carbon I can't tell if they have any markings on top, I've seen the .020 overbore markings on other sets so I know what to look for, I just have to clean them to find out.

I'd dump the carb and get a smaller one, but I've had this one for about three years and man I love it, even with my old performer rpm manifold and a cam set up for midrange she still had enough umph to get the jump on corvettes and firebirds on takeoff.

[sunrunner]

Just got back from scraping on the pistons, holy hell.....

yeah it's bored over a bit.... .060 on the dish of all the pistons.

To think I only paid $1500 for this truck... What a steal.

[Slonaker]

You can't bore it over beyond .060 can you? It sounds like you may have to buy a new one or another one to rebuild.

Slonaker

[sunrunner]

Yeah, apparently we can, I see a set of .080 pistons listed on our online catalog for it, but why bother, the bottom end is still in good condition, a little light honing and I can just drop in a new set of .060 pistons, at least that's what I'm thinking. I shouldn't have to rebore it, should I?

Brandon

[84slopwaggin]

http://www.ryanscarpage.50megs.com/combos1.html

Here are a few combos you can look through to give you and idea of what works with what.

[MylilBowTie]

If it doesn't clean up with a hone. There will be a lot of time and parts wasted. Being already bored .60 is pretty big but .80 the cylinder walls are paper thin. Everyones different but I wouldn't go .80 over on a 350. I would start looking for good used 350 or get a gm universal 350 for around 1500. The engines brand new with new parts not rebuild cores.

Another idea is to have your 350 sleeved but it all depends on what you want.

[Slonaker]

Originally Posted by sunrunner

Yeah, apparently we can, I see a set of .080 pistons listed on our online catalog for it, but why bother, the bottom end is still in good condition, a little light honing and I can just drop in a new set of .060 pistons, at least that's what I'm thinking. I shouldn't have to rebore it, should I?

Brandon

If it is all in good condition, why did you pull it apart?

http://store.summitracing.com/partde...5&autoview=sku If the link does not work, look for part number 10067353.

Slonaker

[sunrunner]

Two years ago while I was heading to work the truck started wheezing and knocking and died on me. I had been having problems with the timing on it and assumed more of the same, but I failed to get it restarted and parked it. The best I could figure was that the cam had jumped a timing gear and needed to be reset. I parked the truck and just now am starting to disassemble it. I am looking for physical signs of trouble with it and am not finding any, so 2 years later I'm still stumped as to why it started acting up. A month before it crapped out on me I had to replace the starter and two alternators, it looked from the gauges as if the voltage regulator wasn't working anymore because it was spiking up to 16 to 17 volts regularly while driving, then the timing started acting up, so I replaced the distributor cap and rotor, but it was still acting up. I could hear a ticking under acceleration so I got home and relashed all the valves. That cured the ticking but a week later it started to knock, adjusting the timing cured that and it ran fine for a week, then it nose dived early that morning and never woke again.

From looking at the internals all I notice is a heavy carbon deposit on everything. Valves seem to be centered up and sealed on the heads with no carbon scoring around the seats, pistons look ok with no holes or dents, nor do I see any scratching on the cups from contact with the valves

The heck with it, I'll just bolt the heads back on and trade it in on a crate one at work. I'll start collecting the vortec heads and parts I want and when the warranty goes up on the crate, I'll start modifying it to my taste.

I had assumed that I could just pass a light hone on the cylinder walls to deglaze them and drop in a new set of .060 pistons with a slightly larger set of rings and make it run, but from what I'm reading here, that's not going to fly. Thanks for letting me know that.

One more question, if I decided to go with a vortec engine, say around a 96-97 model L31 Chevy Motor, can I just drop it in and bolt on that vortec intake with a carb and go, or will it need more modifications?

[Low84]

I'm pretty sure you'd be set if you put the proper manifold and carb.

If you are going for performance though, I recommend that you get that engine that Slonaker was mentioning and save up your money until the warranty ends. Heck you could probably spray it with a 100 shot of nitrous in the meantime. If you really want to go crazy on the engine, you can squeeze out around the mid 700 hp range with nitrous, mid 400 hp without (same engine). This however is SERIOUS power and you need to have forged internals. Which translates into you needing a budget of at least 3 grand for the engine alone.

I personally would rather swap in an ls-based engine, which are relatively inexpensive. The 5.3 and 6.0 engines respond to mods very well and you could see 12's in the quarter quite easily. If you decide to go for a 6.0 be sure to plan ahead. If you plan on running all motor with no power adders, get the lq9 (higher compression ratio) If you plan on adding a supercharger then get the lq4.

I am by no means a performance expert or anything like that, but I do live in a place that is literally filled with performance trucks. Especially the 5.3 and 6.0 and I know what these engines are capable of.

[Low84]

Here is a vid for motivation. I found it on streetfire. 85 500 hp chevy

http://videos.streetfire.net/categor...516A92D700.htm