im startin to buy parts for my 355 buildup i have a 70's 2bolt block (which im getting splayed for 4 bolt) will i have any mounting problems using vortec heads, and i plan on using a performer vortec intake.....will i have any problems using that block with those heads and intake?

 

You shouldn't have any problems. I am using an early 70's 400 block with Fastburn aluminum heads. I am using the Victor jr. Super vortec intake but any vortec intake will work fine.

 

Ive got a 75 350 truck block with 97 vortec heads and an Edelbrock performer manifold. It all lines up ok. Aint the swapability of chevy small block stuff great!!!

 

I would go with the performer RPM intake...the regular performer is a stock replacement..www.summitracing.com part#EDL-7116

 

problem with the rpm is it dosent come with egr.... i want to be able to have my emissions stuff ready in case i need it......is there an airgap performer? if so does it have the egr also?

 

Here is what you do...because I'm not sure . post a topic..What is the best EGR equiped intake for the vortec heads...you willget yor answer!

 

My father did that in one of his old cars and didn't have a problem with that at all.

 

Edelbrock and GMPP are the only companies I have been able to find that make carb intakes for vortec heads. The performer for vortecs is not that bad an intake.

 

yeah I did a little research last night and with a mildly modded 350 you dont really need the higher rpms.anyway Besides its been my experience that the vortecs with stock springs crap out around 5500 rpm anyway...the regular performer will well cover that...now if you are planning on upgrading the vortecs I would look for a better manifold..my .02

 

My 350HO with a broomstick of a cam pulls hard to 5700 rpm with the performer intake for vortec heads. The cam is as follows:
.435/.460 212/222* Duration on a 112 lobe separation.

 

Another source for Vortec manifolds:

Professional Products Manifolds

 

71 4 bolt main here, with vortecs. no problems at all... they will drop onto any sbc for the most part.

I like my performer RPM intake.. no egr though.
she peaks out around 6200, and noses over at 6600.

it's enough to get me to 12.18 @ 111.5mph through the muffler. not too shabby

 

any chance you can share you motor build pony? im only trying to hit mid/low 13's.....but id like to know how you made that power or at least good part combos

 

what cam ya running? Any mods to the heads? If not, I find this kinda hard to believe....

 

It's nice that you want to keep the EGR, but the Vortec head has no crossover provision like the old-style heads did. If you really want EGR, you have to plumb it in off the exhaust manifold. Otherwise, you just bolt up the EGR and connect the vacuum hoses and hope the inspector doesn't know the difference.

 

here's the short version

355, 4 bolt main, 71 truck block.
eagle 4130 forged crank
X rods
Forged flattop trw pistons.
ballanced
Block decked... pistons have a posative .002 deckheight

heads, 062 vortecs.
Bowl work, valve job.
decked, 61cc
stock vavles. Z28 springs

compression in the 10.7 range

vavle train.
Comp XE 274 hyd flat cam. 230/236 duration @.050
crane race cold rockers. 1.5 .. comes out to .487/.490 lift
comp hardened one piece pushrods.

performer Rpm intake, 1" solid moroso spacer, and 780 vac sec 4150 holley.

hei ignition with a pertronix flamethrower rebuild kit.
Slp 1 3/4 headers, y-pipe to a dump, then out to a "catback" or in this case. dump back exhaust.

700R with new guts, 9.5" 3300 stall act converter.
3.73 ten bolt...... pray for this part.

spohn torque arm, sfc's lca's, and panhard rod.


still more in it, opened the dump up last night at the track.. the traction was real bad, and i figured even with it open i wouldn't get booted forno cage.

best was a 1.80 60er. a 12.26 @ 112.5.

it's pretty well untuened still..

 

very nice combo....:hail: Are you happy with that Cam? Its the same I have in my 327...does the ACT stall work well with it? Looks like we have pretty much the same Idea....I like those #'s.

 

how does the XE274 run? it's a little aggressive and definately requires a higher stall....im torn between the 274 and the 268.

i am buying an old 70s truck motor off my buddy's dad, complete, im going to take the oil pan and crank, so my bottom end will be a remachined stock crank, LT1 rods, and some flattop pistons (still not sure what i want, but ill probably go for a summit kit with as high a CR i can get for cost reasons)

 

I love that XE274 cam.

once she's warmed up it barely lopes around at all. the power brakes work, driving it around town is not a problem it's surprisingly docile.
that ACT covnerter's incredible, around town it acts normal, stand on it.. and it tries removing your teeth from their sockets.

i wouldn't call it a daily driver combo. but it's certainly a helluva lot of fun for a play car.

 

12.2's is a VERY impressive....your build doesn't even seem "radical" or overly expensive. You MUST be pushing 400RWHP for that kind of a 1/4 time.

Right now a buddy of mine is building a 350 4 bolt, he's going to use the 268H cam and is just rebuilding an engine that was sitting around but was supposed to be making like 400HP at the flywheel.

Once that is finished then we'll start building my engine. He's a little older then me and wants to have a "daily driver" that he can count on. I'm only 17 and I really don't care...I want the highest compression I can get on premium gas, basically, anything I can do that is cost effective I'll do to get more power. So I'm gonna run the 274H cam...how bad would the launches be with a stock stall converter? I'm getting some parts generously for free from a friend whos helping us do our motor builds, and I'm buying parts on my own as I get my paychecks. Meaning while I would get a new stall for the 274H in the future, right now I have to focus on getting the engine built and running. Then I'll deal with things like my trans and rear as time goes on (I'm definately a "what if" guy and keep asking if the rest of my car is gonna fall apart if the new motor puts out any respectable power). I just read that to put SFC's on I gotta pull my carpet, blah.....

Right now I've got:
2 Bolt 355 (we might take some 4 bolt main caps off an old engine, and "drill and tap" and turn my block into a 4 bolt the cheap way, though I don't think I really need a 4 bolt.)
Pro-Topline Vortecs
LT1 Rods with only 25k miles on them in perfect condition.
LT1 Rockers, retainers, valvesprings


I'm going to buy a complete 70's 350 truck motor off my buddy for 100$, I'm going to take the oil pan and crankshaft, as well as bolts and other various parts I might need. I'll sandblast the oil pan and clean it up. I'm not sure how much getting the crank machined is going to cost me but that'll be done.

So after that I'll get a piston kit from summit most likely because it comes with almost 90% of the remaining parts I need (minus some valvetrain parts, timing chain, etc) Will I be able to get those Speed Pro TRW pistons you used in a summit kit?

I'm guessing the reason your motor is making so much power is because those vortec heads combined with those pistons were a very good match for combustion. I've discussed decking my block with the 2 guys I'm building the motor with and I've been told I can do without it. Is the extra compression worth it? I want the best combustion characteristics possible so I can squeeze as much "realiable" HP as I can out of the motor.

That's pretty much it...really all I have left to do is pick up the old 350 and order the piston kit and a few other little things.
I'm really hyped and any info is really apprciated.

Dave

 

personally i think your buddy's right.. you need a daily driver... that type of motor really isn't. I don't think i've got anythign near 400rwhp... i've prolly got that at the flywheel. clicked off a 12.06 @112.5 today on easter sunday

Well the stock covnerter is an absolute no-no... it'll be a dog. you need a much smaller one, with a higher stall. This motor will without doubt find any stock part behind it in the drive train and obliderate it. take that as fair warning.

unless your running a forged crank i woulnd't run the piston to head tolerances i've got. you don't need it decked below 9' but more compression absolutely equals more power.

10.2-5 will work fine for compression. The summit kit will problaby have all the stuff you need.
on thing you don't need.. a high volume oil pump.. i'd stay away from that. with a stock pan running over 6000rpm.. the odds of you pumping it dry are good.

 

400 at the flywheel and your running almost 12 flat? What year/model is your car?

I was thinking that 400HP at the flywheel would be like 325RWHP, the LS1 is putting out like, 290RWHP and its running 13.5.

As for my buddy, he drives his 86 monte SS 50+miles a day between work and school. I would be driving 15 miles a day between work and school, and I can walk to work (we both work at the same place). The 3rd guy who's helping both of us do this understands that his SS needs to get him further and understands why he wants to be conservative.....I really don't care, I'm 17 compared to 21......I'm willing to go a little agressive and lose a little driveability....I'm guessing your just giving me fair warning that the combo isn't the most friendly....but if it's built and tuned correctly I should be able to drive it w/o any problems right? You said you're brakes work...so you've got vacuum....how soggy is the low end? Is the part-throttle really bad below 2000RPMs? I'm guessing that's the main issue.....was the XE268 cam around before or after the XE274....the guy who's helping me out said that the 268 wasn't around a while back, so the choice was either very conservative or the 274......the 268 is the most you can use with a stock stall and would be more street friendly.....I'll have to weigh my options when the time comes. As for the decking I'll leave it at stock deck.

How fast is my trans/rear gonna go? The car is gonna see duty at the track after the motor goes in....so if I don't abuse it on the street, and put 3-4 runs on it after the swap....is the trans gonna fall apart the first time i get on the car...or do I get a little time?