Hello everyone.... i apologize if this isnt in the correct section.... mods feel free to move it if you wish. I just got my hands on a factory 5sp 86 z28 and it already has a 350 stuffed where the 305 used to sit. My plan is to sit a mildly built 383 in its place. I have a newly machined block and the stroker kit. The stroker has flat top -2cc pistons and 5.7 rods.. with 64cc heads i should be around 10.6 CR. im looking for 4-425 HP at the wheels. the problem im having is what head and cam combo to run. for my build is it possible to run Vortecs to reach my goal? ive heard a lot of ppl say that the vortecs have to short intake runners to meet my goal. also the heads will be fitted with the right parts to accept .550 lift. should i go ahead and cut them for 2.02 1.60s? The cam i was wanting to run is the XE284h. But im not sure how that big cam will work with a manual tranny. Im not looking to go over 6000 RPM but it will occasionaly see 6500 When im feeling really spirited in my driving... This is my first manual tranny SB build so im open to any and all suggestions.... O and im kinda on a budget so i cant afford 1000 dollar heads... Thanks in advance
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im doing a 355 build, and most of the power will come from the heads. i have 041 heads that are ported and filled with goodies. i have around 2k invested in them. as far as a cam. roller cams i think will work best, but there not cheap. the 1 comp cams recommended is 300, but then i need 400 in lifters, matching valve springs, ect...... im sure you might find parts cheaper for yours, but when you start matching parts you will realize its going to cost money. you can pm me and i can give you my parts list to show how crazy it can get.
project-rs
project-rs
Senior Member
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I have a similar setup in my car same cam but with an auto tranny. If that tranny is a T-5 5 speed it won't last long behind that much power. You say mild 383 but that cam and head setup won't be mild. If your planning on running vortec heads you can upgrade the intake valve but not the exhaust (there isn't enough room for both) I run a set of double humps with 2.02s and 1.50s and she seems to breathe enough. My heads have a lot of money wrapped up in them and possibly more soon to come. Originally Posted by kevinstearns
Hello everyone.... i apologize if this isnt in the correct section.... mods feel free to move it if you wish. I just got my hands on a factory 5sp 86 z28 and it already has a 350 stuffed where the 305 used to sit. My plan is to sit a mildly built 383 in its place. I have a newly machined block and the stroker kit. The stroker has flat top -2cc pistons and 5.7 rods.. with 64cc heads i should be around 10.6 CR. im looking for 4-425 HP at the wheels. the problem im having is what head and cam combo to run. for my build is it possible to run Vortecs to reach my goal? ive heard a lot of ppl say that the vortecs have to short intake runners to meet my goal. also the heads will be fitted with the right parts to accept .550 lift. should i go ahead and cut them for 2.02 1.60s? The cam i was wanting to run is the XE284h. But im not sure how that big cam will work with a manual tranny. Im not looking to go over 6000 RPM but it will occasionaly see 6500 When im feeling really spirited in my driving... This is my first manual tranny SB build so im open to any and all suggestions.... O and im kinda on a budget so i cant afford 1000 dollar heads... Thanks in advance You will want to buy the K-Kit (the one that comes with retainer, locks, timing gears, lifters, valve springs, and the cam.) I bought the CL-Kit and added the springs. If they are stock vortec heads you will need to buy the seat and boss cutter and the arbor to cut the seats larger for the springs and allow for the larger lift.
Like I said before that isn't a mild 383 build. If you were looking for mild I would stay with the 350 and just put a little bigger cam in. This cam will not give you much vaccum for power brakes so you will need to either replace the brakes with manual or buy a vaccum pump.
I am speaking from experience with this cam and motor setup.
So should i just stick with machining the stock components? New pistons of course. Slap on my vortecs cleared for higher lift, add an XE274H cam with 1.6 roller rockers, Vortec style dual plane intake, 750 DP, and call it a day? would this setup work better with the t-5? Any info or help would be appreciated.
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im not to familiar with the centerbolt heads. when running a rocker bigger than stock size, its pretty much making the cam think its bigger than it actually is. i think thats why when ordering a cam, it usually says these specs are with 1.5 rockers. do you have the cam specs for xe274h?Originally Posted by kevinstearns
So should i just stick with machining the stock components? New pistons of course. Slap on my vortecs cleared for higher lift, add an XE274H cam with 1.6 roller rockers, Vortec style dual plane intake, 750 DP, and call it a day? would this setup work better with the t-5? Any info or help would be appreciated. Member
From what I understand T 5s blow out behind stock 350s easily all the time, why they weren't offered from the factory. T56 would be a very simple swap, and although a little pricey you'll be more than thrilled with it
RPM range: 1800 to 6000
Valve timing: 0.006
Lobe separation: 110 degrees
Intake centerline: 106 degrees
Duration: 274 Int/ 286 Exh
Duration @ .050" lift: 230 Int/ 236 Exh
Valve lift: .490 Int/ .490 Exh
Lobe lift: .327 Int/ .327 Exh
Comp Cams 12-246-3
These are the cam specs for the XE274H.
A T-56 swap is definitely in the big picture. i just dnt have the money at this point as the engine is currently occupying my brain. Besides, if i grenade the tranny then i have a good reason to talk to the wifey about an upgrade.
Valve timing: 0.006
Lobe separation: 110 degrees
Intake centerline: 106 degrees
Duration: 274 Int/ 286 Exh
Duration @ .050" lift: 230 Int/ 236 Exh
Valve lift: .490 Int/ .490 Exh
Lobe lift: .327 Int/ .327 Exh
Comp Cams 12-246-3
These are the cam specs for the XE274H.
A T-56 swap is definitely in the big picture. i just dnt have the money at this point as the engine is currently occupying my brain. Besides, if i grenade the tranny then i have a good reason to talk to the wifey about an upgrade.

Senior Member
this is the one i have in my 355 now, but switching out real soon due to its way to small. http://www.summitracing.com/parts/CCA-12-211-2/ . sucks that ive never turned the motor over and i cant even use it
Project-RS, I would offer to take that cam off your hands but the Vortecs heads Love split Duration cams and highr lift on the exhaust side. So would the 350 setup make decent power? of am i just spinning my wheels?
Senior Member
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my 355 is rated at 500hp on motor, but it wasnt cheap. 350's can make great hpOriginally Posted by kevinstearns
Project-RS, I would offer to take that cam off your hands but the Vortecs heads Love split Duration cams and highr lift on the exhaust side. So would the 350 setup make decent power? of am i just spinning my wheels? I was kinda refering to the 350 setup i mentioned. what kind of power can i expect?
Ok guys i think im going to go with the 350 setup i mentioned before. i still havent completely decided on the cam yet but im open to suggestions on which one i could use with a manual tranny for my hp goal of 400 whp. "justcallmeclassy" Good news, I found a 98 wrecked camaro with a t56 and got all the parts i need to do the swap for $500. Thanks for the tip man.
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98 is an LS1 car, so if you're using a gen 1 small block the T56 won't work. You'll need one from and LT1 car. If its not an LS1 then its a v6 and therefor a T5, which you already have right?. I'm on a phone right now so I can't see your info but if it is a V8 car you might just wanna grab it and use the rear if you're still stock there, and look into swaping the entire drivetrain over, but 500 seems way to cheap to me for a LS1 T56 combo.Originally Posted by kevinstearns
Ok guys i think im going to go with the 350 setup i mentioned before. i still havent completely decided on the cam yet but im open to suggestions on which one i could use with a manual tranny for my hp goal of 400 whp. "justcallmeclassy" Good news, I found a 98 wrecked camaro with a t56 and got all the parts i need to do the swap for $500. Thanks for the tip man. Junior Member
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Call your favorite cam manafacturer, give them your build specs, car specs, and let them do the cam guess work. There are so may variables to choosing one that it is an art form. What works in one guys car, doesn't guarantee success in yours.Originally Posted by kevinstearns
Ok guys i think im going to go with the 350 setup i mentioned before. i still havent completely decided on the cam yet but im open to suggestions on which one i could use with a manual tranny for my hp goal of 400 whp. "justcallmeclassy" Good news, I found a 98 wrecked camaro with a t56 and got all the parts i need to do the swap for $500. Thanks for the tip man. Bummer... i went this weekend to look at the 98. Sure enough it wont work. thank u all for all ur advice guys. We will see how it turns out and i will post pics in a new thread of my build
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Does it still have the LS1 motor? If so take the motor and drop it in with the t56 and call it done. The LS1 motor is strong and is A LOT more powerful than stock 305. A mild 355 would detonate the t5 easy. Lets put it this way. I had a 350 with a edelbrock camshaft (can't remember the model but small) and 4 lobes rounded clean off on the cam and it still took out 2nd gear. If you want to upgrade for cheap start looking into a built 700r4 that will be your only hope to having a tranny hold up other than swapping to a t56 or tremec tko 5/600Originally Posted by kevinstearns
Bummer... i went this weekend to look at the 98. Sure enough it wont work. thank u all for all ur advice guys. We will see how it turns out and i will post pics in a new thread of my build midias
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T5s were not offered with a 350 for emissions reasons.Originally Posted by justcallmeclassy
From what I understand T 5s blow out behind stock 350s easily all the time, why they weren't offered from the factory. T56 would be a very simple swap, and although a little pricey you'll be more than thrilled with it



