Lg486ta

Hey TGO,
New guy here, first ever post sorry if in wrong thread!!

Ok right to it. My car- 1986 Trans Am 305 Carb Lg4, H code engine. 700r4 automatic trans, 2.73 rear end, all bone stock.

I have a brand new 350 good wrench motor. Jegs# 813788 rated 255hp on the dyno, NOT in car. I have read a lot of posts on here to understand what's up.. Now here we go--> I bought beehive springs and the roller hot cam kit, What intake should I use?? and will my quadrajet work?? I was told and from what you guys have posted I can use my lg4 accessories and starter on this motor???

For those wondering about what will be helping motor? This is what I have--> gta posi rear end 3.42. 11.6" rotors. ceramic coated headers, 89 ta y pipe, magna flow 3" cat, 3" flow master catback (may change), ws6 suspension, B&m mega shifter, trans go shift kit....

I already own motor and parts listed. So feel free to beat me up! That's why we're here right, "do it once the right way, do it forever"

five7kid

iTrader: (14)

Welcome aboard thirdgen.org.

Are you sure about that Goodwrench engine part number? A search on Jegs.com didn't come up with anything.

Assuming this is the base Goodwrench 350, I have some bad news for you - the Hot Cam kit won't work. That's a roller lifter cam, and the Goodwrench engine is flat tappet without the provisions for roller lifters.

The beehive springs will work, but only with the proper retainers.

Your '86 intake manifold will work. A Performer RPM Spreadbore would work slightly better with a cam in the range of the Hot Cam, but you probably don't want that much cam. The Goodwrench engine heads are more for fleet trucks and vans than a performance car, so less cam, like a Comp XE262 would be better, and in that case your stock intake will be fine. The stock carb will be fine as well.

Your accessories will fit. I'm assuming the engine doesn't have a flexplate - if it does, it needs to be 153-tooth (~12.75" diameter), and not 168-tooth (14" diameter). With a 153-tooh flexplate, your starter will work. But, your '86 flexplate won't fit on the Goodwrench engine, because the '86 is 1-piece rear main seal, and the Goodwrench engine is 2-piece rear main seal, and the bolt pattern (among other things), is different. Not a big deal, get a stock replacement for an '85 Firebird V8 auto trans (not too expensive, ~$40).

Lg486ta

Ok, first sorry About pt# I was wrong it's 260hp Not 255. http://www.jegs.com/i/Chevrolet-Perf...oductId=752506. As far as hot cam, no worries. I have an xe262 for lg4 never got used! Iv also read, that the 416 lg4 heads ported and rebuilt would raise compression and be big improvement over good wrench heads?? True or false??? Flex no prob either. What rods and hangers would you recommend for this set up??

Lg486ta

Almost forgot, what about fuel pump??

five7kid

iTrader: (14)

Okay, that's what engine I assumed you meant.

The listed specs:

"4-bolt main with 2-piece rear main seal" - you'll need a flexplate as I described above.

"Cast pistons (dished)"
"Cast iron cylinder heads with 76cc chambers"
"8.5:1 compression ratio"
This is why the LG4 heads would be better. That, and better ports. Even unported, the engine would make more power with LG4 heads than with the heads the factory used. Ported, with 1.94" intake valves, the LG4 heads would be even better.

"Hydraulic flat tappet cam (.383''/.401'' and 112° lobe separation)" - If you have an XE262 with new lifters, then that would be the way to go.

You'll have to use your fuel pump push rod and mounting plate, but it is made for mechanical fuel pump.

DR rods are pretty popular. There are a couple of other reasonable choices. People seem to recommend a B hanger a lot, mine was an H. It ran well enough (ZZ4 clone) that I never bothered trying any other hanger. The DR rods, though, made a big difference.

Lg486ta

Hey five7kid. I apologize for my stupidity!!
http://www.jegs.com/i/Chevrolet-Perf...oductId=813788.
This is my engine. I have the roller cam 255hp, same as this one. That's why I wanted to go with the (Hot Cam). When you said (flat cam) I got all confused. My spec sheet with my engine says the roller cam. And Vortec heads, they are way better then my lg4s. Again sorry for being so dumb. Makes much more sence to ME now!! Thanks again for the help.

Atilla the Fun

It's advertised as 8.5:1, but the reality is 8.0:1 with steel-shim head gaskets, or 7.8:1 with composites. As such, any cam larger than Comp's PureEnergy will hurt the compression situation enough to feel. Try to trade those heads to a machine shop in exchange for a rebuild of your '416 heads off the 305. Then look at something like an XE262.

Atilla the Fun

You don't need to port the 416s to feel an improvement, and be aware that 260 gross HP is nowhere near 260 net HP. A stock Goodwrench won't run with a stock L98. To get 260 HP out of the Goodwrench requires putting it on a SuperFlow engine dyno with an aftermarket intake manifold, long-tube 1.625" open headers, an electric water pump, no p/s pump, no smog pump, no alternator and no a/c compressor. That's gross HP.

Lg486ta

@ Atilla. This is my engine specs. I got confused in earlier post.

Vortec cylinder 64cc heads (1.94" Int/1.50" Exh valves)
Nodular iron crankshaft
Powdered metal connecting rods
Hypereutectic aluminum pistons (9.4:1 compression ratio)
Oil pan
Timing cover
Valve covers
Harmonic balancer
Roller cam (Lift .414" Int/.428" Exh; Duration @ .050" 191° Int/196° Exh; Lobe Separation 111°)

My first engine build. So bear with me and my mistakes
Thank you

Atilla the Fun

Those are the specs for the replacement L31 for '96-up. But you can't get that engine for $1700. It does make 255 net HP, and those are great heads, but that engine will run you NO less than $2300. Plus tax or shipping, depending on where you get it. The $1700 new 350 is the low-compression Goodwrench 350 with the heads nobody wants. I vote spending the extra money and starting with the L31, but not even Jegs is gonna sell it for $1700, not even on sale.

Lg486ta

I already have the engine. Through jegs after tax was almost $1,800 and free shipping!! Look at my link 5 posts up that is the engine for $1,779.99.
The hot cam I was told is the way to go? Is the LT1 or LT4 better ??

InfernalVortex

iTrader: (4)

Wow... thats a great deal if thats really what you got. Can you pull the valvecovers and see what head casting numbers you have just to make sure? If you got Vortecs, you are almsot guaranteed to have a roller cam. You can run those beehive springs and Hotcam and have a REALLY nice motor that way. Just get the 787-16 retainers and be meticulous about the installed spring height.

It makes a HUGE difference which engine you have to make decisions about what you need to do to it.

With the vortec setup and the hotcam you may be pushing 350-375fwhp. Enough to get your car into the 12's probably.

1gary

It is a important detail you pay attention to degree the cam you put in.

Lg486ta

My mechanic buddy helping me with engine said head stamps are 060 not 906. Is that really a roller cam?? I don't know by looking at it just what sheet says from jegs. I will have pro install cam and adjust for me. I don't know much about installs!

vetteoz

iTrader: (13)

hell of a deal for a L31 roller cam short block
If that is what you have the Hot cam is a slip in replacement but you will need new valve springs in the Vortec heads
for the higher lift

Lg486ta

I'm going to truck this engine down to my local Chevy dealer and I'd this engine for real. If it is actually a roller. What would be good intake?? Everyone says edlebrock performer. But there's a bunch. I want idle -5500 power. So do I just look for one in that range. I understand needs to be vortec specific if indeed vortec heads.

@vettoz. I have the beehive springs and lifters to match with the hot cam. I own them all ready that's why want to know if it will all work?
I don't want to (Frankstien) an engine that may not work. I'd like to do it right the first time.
Thanks guys for helping me with this!!

InfernalVortex

iTrader: (4)

Vortec heads are 062 and 906. What is interesting is I know the GM part number for Vortec heads ends with "060". I always wondered if there were any heads out there with that numbering as the source I had for that wasnt too clear on it. Normally you order the 060 heads and you receive 906 or 062. Thats definitely not the phone company van heads for sure, and it matches the GM part number for Vortec heads. If there were 060 Vortec heads out there, they would definitely be on these brand new crate engines. Im 99 percent sure you got a legit roller block vortec engine.

Another way to check just to satiate your own curiosity is to count the number of bolts holding the intake on. Vortecs only have 8 different intake bolts. 2 at each corner and no middle ones like every other sbc head.

And I would, especially with an LT4 hotcam, get a Performer RPM, not a plain performer. Regular performers are stock replacement type intakes and are great for getting a nicer look and maybe a little more power out of an otherwise mostly stock engine. but the LT4 hotcam is a big enough cam to warrant a little better breathing. They're also VERY well suited to the Vortec heads, which is no surprise since they're optimized LT1 heads. The RPM intakes say 1500-6000 RPM power band usually, but I have no problem with mine cruising at 65 mph on the interstate at 1200 RPMs. I think the Hotcam will push your power band up enough that a regular performer will cost you some power. The Hot cam isnt going to have off idle power anyway, it probably wont kick in until around where mine does... 1200-1400 RPMs, so getting an intake that is designed for a stock sized cam wont really do you much good. The Performer RPM is still a dual-plane intake and you wont have any problems with low end torque with the combo you're planning. It's probably the best bang for the buck, streetable performance combos out there for the Gen I sbc.



You wont have any problems with an RPM intake unless you try to run a huge air filter.

If you can swing it, i'd recommend going EFI and getting a Holley Stealth Ram setup, but if thats too spendy for you the Performer RPM is the way to go. If you can find a used Vortec Performer RPM Air Gap that will work just as well. They're a little more expensive and are a gimmick. They dont really get you any extra power, but if you find a deal on a used one grab it. The RPM Air Gap models and regular RPM models have the exact same ports and will flow the same amount of air, just the air gap looks cooler. Just dont ignore an Air Gap version if you see one cheap.

Lg486ta

Ok so gm confirmed it is the roller motor.
Im staying carbed, so Performer rpm will be added to the list.
I'd like to be able to highway drive. So was wondering about gears. Would 3.42s be better. I own 3.73 if not?
I'll try n put up some pics. Cars in black primer with no wing

InfernalVortex

iTrader: (4)

What transmission are you running? If a turbo 350 i wouldnt go past 3.23's. If a 700r4 I wouldnt go past 3.42's. T5 I would go with 3.42's, and T56 you can even go with 4.56's if you want to. What do you want to do with the car? Race it? Just drive it?

Make sure to get a VORTEC version of whatever intake you end up getting.

Lg486ta

700r4 auto. 3.42 is better? One thing I did know is with vortec heads has to be vortec compatible intake

Lg486ta

Sorry. Car will be street driven. Few track trips just to know where it stands.. But street driven mostly

InfernalVortex

iTrader: (4)

A well tuned carb with a RPM intake and an LT4 hotcam and 3.23-3.42 gears will be a great fun street car. Should have great throttle response and great power.

Make sure you put a decent exhaust system on it to get all the potential out of it, but you're gonna be real happy. You could make more power if you wanted, but it would start costing a whole lot more money for a lot less gains from where you're at now. You're at the perfect hp per $ mark there and it's still respectable numbers by modern standards.

Just make sure you have a good posi!

Most importantly ,you'll be making about twice as much power as all the guys who bought that awful phone company van engine we were all worried you got.

Black 84 Z

Does your engine have a provision for a mechanical fuel pump? Most L31 blocks do not, but it appears from the picture that this one does. Great find BTW, Most I have seen have been over $2000.

five7kid

iTrader: (14)

The boss is cast into all of the blocks. Some of the later ones just didn't have the pushrod and oil drainback holes drilled/bored.