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#1
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Going from a 350 to 400.
First off, I'd like to say "thanks" to all of the regular and semi-regular contributors here on this site. It was recommended to me a few months ago, and I have been doing a lot of reading and this is going to be my first post asking for a bit of advice.
I'm fairly new to Pontiac ownership, though I have lusted after 2nd generation Firebirds ever since I saw our favorite Burt Reynolds move (no, not Deliverance). I picked up this hunk of burning love this past summer: The previous owner had done a pretty good job with a rattle can paint job (as far as rattle can jobs go). He used Kubota tractor paint, which was actually a really good choice for Pennsylvania because it is heavy duty and corrosion resistant. Still, I didn't like looking like a traffic cone and ended up changing the looks a little: This is how she sits now: It's "Imperial Blue Metallic", not black. It isn't a real TA either. This car began it's life an as Esprit, and the cool spoiler and TA front end came later. The orginal motor was replaced with a 350 out of a 69 Firebird. When I bought the car, it was advertized as "recently rebuilt, balanced and blueprinted" etc. Long story short, the motor wasn't rebuilt. It's an old/tired Pontiac 350 with an aftermarket cam as likely the only internal modification. I'm also pretty sure that the cam is eating itself because there is metal like sand under the valve covers and the valves clatter like crazy. It's also down to running on about 6 or 7 cylinders. Knowing that the 350 is about dead, I purchased a 400 from one of the more esteemed members of this forum (Singleton) and brought it to the shop on Saturday. Disassembly begins tomorrow, and barring any unforeseen problems with the motor, it'll go to the machine shop later this week for any re-boring and other machine work that needs to be done. After that, the guys at the shop that are going to be putting it back together and into my car for me await my shopping list for the engine build. Singleton tells me that the casting number is not one of the more desirable ones, and that I shouldn't try to go to crazy. That's fine, I'm not looking to build a drag car and with a turbo 350 and 2:73 gears that I don't want to change ($$$) behind the motor, it isn't really an option now anyway. I'm looking to build a nice street machine, daily driver fuel economy, but nice power and pleasing to the rest of the senses. I'm looking for specific advice on: Pistons. Do I go with something close to stock, or is there a "go-to" performance upgrade that is considered standard? Cam. The engine guy at the shop is very fond of the Lunati "Voodoo" cam. I'm open to any advice or experience with this or any other cam recommendations. Carb: I have an edelbrock 600 CFM on the 350. I'm thinking this can move right on over to the 400. If that's stupid, tell me. Intake: The 400 has the stock 4 barrel intake on it now. Problem is that I don't know if the shaker will fit. The 350 has an Edelbrock Performer intake on it that can move over to the 400, but I'm advised that the stock intake has better flow numbers than the Edelbrock. If the stock intake doesn't work with the shaker, can anyone advise a good intake that will work with the shaker and provide good airflow? Heads: These are going to be stock 6X-8. The heads on the motor should be good, and I have an extra set as backup just in case. Anything else you can think of to help confuse the hell out of me would be great. Please remember, not building a drag car. I'm driving this fella to work and the drive in. Thanks again. NH16 |
#2
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Your car looks very good but I will leave the advise to the experts.
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#3
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If the 400 is a low compression later one, I would not go with a stock cam at all. Even though it may have low compression you can change the cam and pistons and bump up the HP to make it feel a lot faster.
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1971 Pontiac GT-37 Car is a junk yard dog and maybe one day will be restored. |
#4
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i'd stick with the stock intake, but you'll have a mismatch with your carb. you can either open the stock intake up like Cliff R's or get a Q-jet.
6X-8's on a 400 are pretty big chambers, either cut them down or pick your cam wisely. you don't want to over cam with low compression. |
#5
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do u have a number in mind(budget?)
i have a project on it's way right now similar to yours. going from a 350 to 400. i built the lower end a little stronger using the stock crank but new pistons and rods. machining of the block,pistons,rods and bearings and you will be at 2200 in no time.
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#6
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Quote:
I'm all ears for any suggestions on choosing my cam wisely. |
#7
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I think the 76 stock intake is restricted in the secondary opening area. I would use the Performer but port match the openings a little.
Use the 4 eyebrows forged pistons, not the 8 eyebrow cast ones. Use the Q-jet and have it modified. It's 750cfm but 300 on the primaries. Wack the heads .030 and the intake should still fit. With 2.73's keep the cam in the 214 to split 226 range at .050 I like the 265 or 275DEH Comp Cam for your combo. If it's a #557 casting block your gonna keep the hp under 350 anyway. |
The Following User Says Thank You to PONTIAC DUDE For This Useful Post: | ||
#8
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Which heads are on the 350? You could use those.heads to get a better comp ratio, and sell the 6x-8.
Even though your not building a drag car, I dont know anyone including myself, who owns classic muscle or sports car that doesnt get on it whe they go for a ride Nice car you have. I'm no expert just my :2cents
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78 T/A 4SPEED, Original paint, match #’s, stock original bottom end, milled 6x-4s, HE268H cam,17058263 Q-jet/ 72 jets, CH secondary rods, RA Manifolds, poly body bushings, Moroso SFCs,mine since ‘99. 79 Parisienne just got it 77 t/a sold 85 Monte Carlo SS sold 83 Mustang GT sold |
#9
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Good job on the car so far!
Pretty much what P-dude said. To clarify a couple things for you: All Pontiac V8s are the same external dimensions so an intake that works with your shaker on your 350 will work on any engine with your shaker. The Performer is intended as a stock replacement intake so same height as a factory intake. Might as well use the Performer - I don't think it's going to hurt power at the levels you're building for but it's not as good as an early (pre '73) factory intake. Quote:
Seriously, a Q-jet is a way better carb. Never liked those Carter/Edelbrock carbs.
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---------------------------- '72 Formula 400 Lucerne Blue, Blue Deluxe interior - My first car! '73 Firebird 350/4-speed Black on Black, mix & match. |
#10
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Quote:
What are the 350 head castings??? Q-jet w/o doubt. Do you have a carb number? The secondaries on the stock EGR are restricted, but it's still a good piece for a conservative build. What's wrong w/ the 400 as it sits??? I'd look at the cam lobes and bearings, before ripping it completely apart. You might have something that could be used w/ a minimal amount of $$ being thrown at it, If it's a 557 block I'd consider it even more, freshen it up, use it as your new "temp" engine. and gain a very noticeable amount of performance, even though it's a low compression 400. Just a thought, if nothing else... Car looks very nice!!!
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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
#11
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Got into the 400 today, and it's gonna be a coin flip if it is rebuildable. 4 of the cylinders had water in them and were pretty rusty. I don't think it had ever been bored, so it might have enough left to clean up, or we might sleeve it.
I'll look at the heads on the 350 tomorrow and see what numbers they are. I'm gonna google "4 eyebrows forged pistons" right now. Thanks for the advice on the intake, carb and cam. |
#12
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Quote:
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Will Rivera '69 Firebird 400/461, 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears ‘66 Lemans, 455, KRE D-Ports, TH350, 12 bolt 3.90 gears '69 LeMans Vert, 350, #47 heads: work in progress |
#13
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I ran a Comp XE262 cam in a 400 with 6x-8's. It was still a butt-ton of fun as a street motor even tho compression was low. That cam pushes the limits of stock valvetrain. I ran it with new Comp springs.
I wouldn't sleeve a 557 block. I have one sitting in my garage that I bought for cheap as a complete motor and it sits waiting as a bare block for when I get the urge to have a last resort dirt-cheap disposable build, or a driver motor. Get the block checked out, maybe bore it if it needs it, but definitely find a better casting if you are going to go as far as bore/sleeve. If it didn't have the rust issues as stated and the bore was in good shape, I'd be tempted to go ultra low $$$ - rering the 400, throw in a Summit 2800, maybe 2801, new gaskets, and see what flies. But it sounds like you are beyond that point. But then again, I'm a guy who plans to turbo a 350, which is an engine most Pontiac guys wouldn't waste their engine build $$$'s on. Someday I want to be the guy on the forums who pushes a weaker 557 block way past what everybody expects of it for super cheap. At times I have more dollars than sense. That is a sexy T/A. Me likes.
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"...ridge reamer and ring compressor? Do they have tools like that?" |
#14
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^^This. Good cam choice for low compression engine. The cost of sleeving even one cylinder in that block will probably exceed the value of the block.
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---------------------------- '72 Formula 400 Lucerne Blue, Blue Deluxe interior - My first car! '73 Firebird 350/4-speed Black on Black, mix & match. |
#15
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Thanks for all the great input guys. We will have a verdict on the 400 block on Friday. I'll keep you posted.
PONTIAC DUDE, I looked up the pistons you reccomended, and I think they are the same ones that are in this kit: http://www.summitracing.com/parts/fe...w/make/pontiac Did I find the right ones? I know I gotta wait until the machine shop does it's work before I order. |
#16
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Rusty, as in, a lot of surface rust?, or corrosion rust?
I'm not a nay sayer, on much. Most here won't have a 557 block for a door stop. If the block needs sleeves, it will only make that weak block weaker... Be careful on letting the machine shop make a decision for you by default. It's a good bet they may not know much about Pontiacs. mIf the block would clean up @ .030, that might be O.K. I'm sure you would have to bore the block more than that for sleeves... There's a boat load of Pontiac enthusiasts in Pennsylvania, I bet there's a good block near you!!!
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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
#17
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Corrosion rust. It was bad enough that it looked like dirt, but it was just rust. I don't think the block is going to be buildable. The early returns from the machine shop was laughter, so that isn't a good sign.
I need to update my profile, I'm down in Pensacola now. Got an an instructor tour at Navy Chopper Command. |
#18
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77 400 for sale
Check out the "performance parts for sale". '77 400 for sale in Florida for $750.00. Ed
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#19
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Davie FL is in the same state, but a 1300 mile round trip from where I am by Pensacola. Thanks for looking out though.
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#20
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Shipping
You could probably ship it for a couple hundred bucks. Ed
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