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1996-2000 vortec block build

19K views 33 replies 13 participants last post by  idontdrivericeieatit 
#1 ·
i have a STREET car 69 chevelle,1975 305,(29-3200 stall convertor) th400, and 3.73 rear.
I am on a budget, looking to put a 350 in with up to 400hp and torque. The late model vortec engines have a stronger bottom end than the earlier style engines.
Now, I dont have to get the motor to my hp and torque goals right away. At this point, I want that 305 out of my car. So Im looking to just put the motor in with a stronger bottom end. Then down the road change the top end.I can transfer parts from the 305 to this motor. My question is will a 1996-2000 vortec engine, be the right choice for a good foundation? Finding a remanufactered long block should be easy.
Also does it have mechanical fuel pump provisions?
 
#4 ·
Any good 350 short block should be able to handle 400hp/tq. If you can I would try to get a block with roller cam provisions, 4 bolt mains, and flat top pistons. Those three things will give you a great set up to build a strong engine down the road. If you can I'd also spring for 6" rods, a nodular or cast steel crank, and the best balance job you can get. A high volume oil pump is a cheap upgrade and while it may not be absolutely needed, it's cheap insurance. If you can afford it forged pistons with a thin ductile iron or steel ring set are also great.

Getting all of the things I recommended will set you back a good amount, keep in mind there is a BIG difference between a run of the mill reman enigne and a top notch custom built engine.

Going cheap isn't a crime, but if you want to get something really nice I'd look for the things I mentioned. A 3.75" stroke may be a consideration too.
 
#12 ·
I'm with you until you get to the 6" rods and needing a 4 bolt main.Ring spacers because of pin placement and mm ring sizes for long mileage use on the street isn't what I would suggest.Two bolt blocks for street use at 400 hp would be fine.If later he wanted more,he could go the splayed mains which would be a much stronger part than a OEM 4 bolt.
 
#7 ·
The Vortec is not fully machined for a mechanical fuel pump, it can be finished off however. The Vortec timing cover is plastic and does not accept changes to the OEM timing gears and chain without some effort. They can be backdated to a metal timing cover. The question gets to the cam whether you want to keep it a roller or convert back to a flat tappet.

The cylinder walls don't extend as deeply into the crankcase as older 350's which simplifies putting a stroker crank in there but also reduces some support for the piston skirt, this pretty much demands a hypereutectic casting or a VMS-75/4032 high silicon forging in order to minimize the skirt clearance so high accelerations from wide clearances can't happen when the thrust sides change at BDC.

I'm not impressed by GM's powder metal rod, I certainly wouldn't use it for any high performance application.

It seems you have a pretty high stall converter is this because the 305 is running a big cam? A 350 running Vortec heads, Performer RPM intake, Holly of 650 to 750 CFM, a Comp XE 268 or any of the aftermarket equals to these can easily get to 370 hp and with some tuning, porting, 1.6 rockers, big tube headers and certainly a 750 cfm carb will go to 400 or so. Piston choice plays big on the low through middle high RPM power. A D-dish or flat top piston in-place of the OEM round dish piston for a common compression ratio of 9.5 to 1 and holding the squish/quench dimension to not more than .040 really wakes up the middle RPM ranges with as much as 20-30 foot pounds of torque and 10-20 horses. The round dish piston output converges on the D-dish or flat top at peak RPM but under that the better piston really carries the day with a fatter power curve. This curve also carries a slightly higher power peak at a bit higher RPM with a slower decay than seen with the round dish piston.

Bogie
 
#8 ·
the reason why im running a high stall convertor is, at the time i was having my TH400 installed I wanted a wicked big block so that convertor was picked according to the engine by the trans company. years later, I've decided to just keep it a small block for driveability and price.
 
#9 ·
You can get a 96-2002 2 bolt longblock for $2200 and a 96-2002 4 bolt L31 longblock for $100 more.

-Roller cam equipped
-forged Powdered metal rods(stronger than the old Pink rods)
-nodular iron crank

With the cam that comes in it, 191º/196º 0.412"/0.428" 111ºLSA expect around 310-320 gross hp.

Great beginning for a nice street engine.

peace
Hog
 
#10 ·
Then down the road change the top end.I can transfer parts from the 305 to this motor.
Be careful here. Bolting the 305 heads to a 350 block and using a short duration stock cam could raise the dynamic compression ratio into the threshold of detonation, depending on fuel quality. Resist any thoughts you may have of using two head gaskets to lower static compression ratio. That'll just make it worse.
 
#13 ·
I don't think,given you saying the plan was for a BBC in the beginning,your ever going to be happy with any SBC.Sometimes your first gut feeling is the right one.And in this case I think your right.

Here is what I suggest you do before you spend the time and money on a SBC.Call Pat McCarthy of McCarthy Performance.Techinspector1 would agree with me he builds some of the most rightest BBC's at very reasonable prices.It is kind of his specialty.Do talk to Pat and if you like,tell him I told you to call.

McCarthy Performance / Racing Engines to 632+ Cubes

He'll build you a pretty shout SBC too if you like.
 
#15 ·
Metric low tension ring sets do not have the same sealing capabilities as a standard set.They are more appropriately used in a race set up where drag tension is a concern.I don't want to open the topic of long rod vs short rod debate.I in fact believe in the use of long rod engines.What get's more complicated is whether the trade off of ring spacers is worth the long rod in a relatively low compression street application.I'm saying it isn't and in fact the longer rod (6" vs 5.7")isn't going to make that big of a difference.That we build long term good sealing street performance street engines that are reliable.
 
#16 ·
metric ring sets seal BETTER- which is why OEM's have been trending towards thinner rings for decades. and as I already noted a 6" rod DOES NOT require oil ring support on a 3.48" stroke. If you need new rods and pistons there isn't a single reason in favor of a 5.7" combo.
 
#20 · (Edited)
Just saying "metric rings" leaves a lot out of the picture IMHO. There has been metric rings used in GM production engines for quite some time now- including the Gen 1 and 2 SBC. So to say 'metric rings' does not necessarily say anything is all that different that can't be handled by a competent machine shop (tension, materials, honing finish) other than the measurement system used to measure the rings. In the case of the SBC the top rings measure the same thickness for all intents and purposes, while the second rings are marginally thinner than the old fractional ring sets.

Example:

A 5/64" ring = 1.98mm. The LT1/4 Gen 2 engines and the later Gen 1 engines use a 2mm/1.5mm/4mm ring package. The second ring is akin to a 1/16" fractional ring. Radial tension may be less, but it does not HAVE to be so.
 
#21 ·
A proper gaped 5/16 compression ring for it's application is going to provide 7 to 8 pounds of tension.
Certainly ring material,our competent properly prepped cylinders all come into play in the final sealing power.

We don't go by OEM standards when that hasn't been the point of hot rodding from the beginning of time to current.Some of the stuff they do is just pure cost cutting.

These comments are related to first gen blocks and street/strip applications.
 
#22 ·
Most people use the OEM standard as the lowest acceptable standard- they try to do better. In fact, you're the first hotrodder I've found that sets their standards as higher than the target.

If you want to know all of the why's on why thinner rings are superior then call Total Seal- they've never steered me wrong and I'm sure they'd be glad to help you out too.
 
#23 ·
Last year I was on a budget and I found a 350 3/4 ton truck that my uncle had and I took the engine out. I had some heads that were alredy checked out fine by my machine shop that were off of a 305 or 307 95 c10 I think it was. I used those heads and had a cam that I bought for 50 bucks. All I know about the cam is that it has 383 lift. Also have a edelbrock performer intake. Well I built this engine and it got unbelievable power. I dont know if its cause the 305/307 heads put off high compression or what but I run the car (79 El Camino SS) on 87 pump gas. It sound mean and drives like a champ. One thing I would consider is your transmission and gears. I have a muncie 4 speed and 3.73 gears which thats where I get alot of power from. Im also usin a stock Q Jet carb. So I guess what Im getting at dont worry about 400 HP and just build a good reliable mean street motor using GOOD used parts like an assembled block find some good vortecs (L31) heads like you were saying you wanted, if you can and just buy a good cam. All those vortecs can handle stock is .425 Lift but still would be a hell of a motor.
 
#31 ·
And sorry but if you think a 350 with 305 heads and a 383 lift cam which I didnt even know they made them that small makes unbelievable power then you dont know what real power is you would be lucky to make 200hp now the 400 is heavy and prob is costing him a few hp to rear wheels but motors not going make any more power no matter what gear or trans he has gear and trans just puts power to the road
Hey Pugsy.What up??.

I knew what he meant too.

We had a guy with a 350 Vortec Goodwrench crate in a 4,000 Astro van(yepper that's there wt stock) use that "383" cam with a mod'ed TBI and chip burn.Now not everything has to be over 500 in a lift to be a decent cruiser.Surprising mid curve and very good,no great,street manners.For some that would be a worth while venture.Because of the way the thing pulled in the mid section on a 4,000 van,I would think it is all of 300hp.
 
#25 ·
And sorry but if you think a 350 with 305 heads and a 383 lift cam which I didnt even know they made them that small makes unbelievable power then you dont know what real power is you would be lucky to make 200hp now the 400 is heavy and prob is costing him a few hp to rear wheels but motors not going make any more power no matter what gear or trans he has gear and trans just puts power to the road
 
#27 ·
Yes it is .480 max lift. And Yes the engine I stated ubove is a nice mean street engine ON A BUDGET. No it doesnt have huge HP but I was saying not to worry about HP espeacially since he said he is on a budget. Just build a good reliable engine with parts that is in his price range. And I know for a fact my engine has more than 200 HP. Might not have 300 but it is a good reliable engine. And it runs awsome. And gears and a tranny def helps out with whatever setup you are going to have. Also I never said you used vortec heads. The OP was asking about getting one.
 
#28 ·
(And gears and a tranny def helps out with whatever setup you are going to have.)
what car does not have gears and tranny?
gear ratios can be changed for specific applications,,,
The absolute cheapest way to make a car quicker is to reduce the weight.some weight reduction can be done for the cost of labour alone.
 
#33 ·
"383 lift" could mean lobe lift. I just love it when statements are made so clearly. No decimal points, no nothin'.

As far as "everybody I know says they (L31 Vortec heads) will support 480 lift stock"- do NOT count on it. There have been cases where they will allow 0.480" lift, but that's going to be w/o much if any leeway between the retainer and seal at max lift. There are easy and not so easy ways around this, but in stock form this is a total crap shoot. More on L31 Vortec heads here.
 
#34 ·
Yea thats why I say I dont know for sure I have no personal knowledge. Of vortec heads as I dont and havent ever used them I was just going by what people say me im a big fan of afr since my first set not going back now plus with the solid roller cams I like to run it would cost me to much to get a set of vortec where they would need to be
 
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