1995 K2500 350 full performace rebuild

[Komet]

Flat tappet cam is an automatic no, aluminum rockers also no for durability reasons. You want a dual plane intake for this application, electric waterpump is not needed because you don't need to run the pump in the staging lanes, neither is a special oil pump. Upping the displacement to a 383 is a great idea, don't need forged equipment unless you're doing forced induction.

 

[Ekays]

^^^These...
It's funny, I just took my 88 today with this Blue Print short block, my own heads and running TBI still. I was having so much fun smoking my one wheel peel 275R/60 tires at part throttle

After rebuilding/modifying 2 350s with flat tappet and roller cams I'll never go back - it's just too much fun but, I'll need to get a locker or some kind of posi for it - maybe even wider tires too

One thing I know - I'll NEVER RUN A FLAT TAPPET cam again!

GM SB Compatible 383 c.i. Engine - 436 HP - Short Block Plus

Description: HP & Torque: 436 HP / 443 FT LBS Compression Ratio: 10.0:1 Hypereutectic Pistons Cast Steel Crank Block: 4 Bolt main 4.00" bore Passenger side dipstick Align honed main bearing bore Cylinders honed on computer controlled machine to within .0002 straightness and roundness Cylinders...

blueprintengines.com

They have long blocks on this site too...

Why no flat tappet? What does it take to keep the stock tbi? I know there's threads about this but I'd like to know how you went about it

 

[Supercharged111]

From what I can gather this should get me in my desired hp/tq range and run fairly reliability.

Questions:

2. Am I going to make the kind of power I want?

1: what is your desired HP/tq range?

2: what are your expectations for drivability and low end torque?

 

[b454rat]

I built 2 454's and neither of them had any forged parts. One had aluminum heads, made around 550 horse. Last one was 400-ish. Both were nothing exotic, other than the heads. Today's oil sucks for flat tappet cams. Go roller and get some extra horses while ur at it.

 

[PlayingWithTBI]

Why no flat tappet? What does it take to keep the stock tbi?

Years ago, we had high zinc and phosphorus (ZDDP) oil which helped lubricate flat tappet cams. Now we have EPA required high detergent oil which doesn't allow the zinc coating to build up thus, exposing the bare cam metal and lifters for more wear. High ZDDP will plug you catalytic converter too. I know diesels run high zinc oils but, they use a different style Cat. That's At least that's what I read.

Here's some "light" reading for your enjoyment. I go through what it takes to convert to a roller cam but, if you don't have the bosses for a roller, you'll have to go with link-bar lifters. There's some tuning towards the end. Note; my TBI isn't stock, it was bored to 46mm and I'm running higher pressure springs. Enjoy!

My Flat Tappet Cam Wiped Out So I Decided To Go Roller

A little background: About 4 years ago, my '88 C1500 with the 5.7L TBI engine started overheating on me. I found the head gaskets blown. I knew the swirl port heads and peanut cam were about useless so, I decided to "upgrade" to better parts while trying to keep it fairly cheap - yeah right...

www.gmt400.com

 

[Ekays]

1: what is your desired HP/tq range?

2: what are your expectations for drivability and low end torque?

380 hp/400 tq ish would be perfect

Right now I can cruise right up pretty steep hills in 3rd/4th (I have the 5spd as previously mentioned) in the 1000-1200 rpm range (thanks 4.10 gears) and id like to continue to do that. From what I've read as long as I don't go too crazy with my cam I can keep my low end.

I built 2 454's and neither of them had any forged parts. One had aluminum heads, made around 550 horse. Last one was 400-ish. Both were nothing exotic, other than the heads. Today's oil sucks for flat tappet cams. Go roller and get some extra horses while ur at it.

Would a zinc additive make a difference? Is there any solution for the oil problem?

Years ago, we had high zinc and phosphorus (ZDDP) oil which helped lubricate flat tappet cams. Now we have EPA required high detergent oil which doesn't allow the zinc coating to build up thus, exposing the bare cam metal and lifters for more wear. High ZDDP will plug you catalytic converter too. I know diesels run high zinc oils but, they use a different style Cat. That's At least that's what I read.

Here's some "light" reading for your enjoyment. I go through what it takes to convert to a roller cam but, if you don't have the bosses for a roller, you'll have to go with link-bar lifters. There's some tuning towards the end. Note; my TBI isn't stock, it was bored to 46mm and I'm running higher pressure springs.

Cats aren't an issue, I live in Washington where there's no emissions testing so I won't be running cats.

Worded that badly, obviously not a stock tbi but what all did you do to modify your fuel system to support your build?

Thanks everyone

 

[Hipster]

I stay away from fast-rate hydraulic flat tappets. More cam leads right into tuning.

 

[Sean Buick 76]

Each to thier own but a mild fiat tappet cam for the idle to 5500 range isn’t hard to make live with todays oil selections. The roller cam has little advantage over a fiat tappet in the close to stock rpm ranges.

When going with aggressive cam lobes and big lifts is when it’s tougher to keep flat tappets alive. Also with these exaggerated valve events is where the roller cams shine.

Many people just prefer the rollers and I understand however used properly there is a place for the fiat tappet even today. An example is in on Buick engines that I’m into. For a 350 Hp buick 350 either fiat tappet or roller can do this easily but it’s an extra $1200 to go the roller route fir very little gain other than skipping the break in routine. If a block is roller ready then most just go that way.

 

[Hipster]

Each to thier own but a mild fiat tappet cam for the idle to 5500 range isn’t hard to make live with todays oil selections. The roller cam has little advantage over a fiat tappet in the close to stock rpm ranges.

When going with aggressive cam lobes and big lifts is when it’s tougher to keep flat tappets alive. Also with these exaggerated valve events is where the roller cams shine.

Many people just prefer the rollers and I understand however used properly there is a place for the fiat tappet even today. An example is in on Buick engines that I’m into. For a 350 Hp buick 350 either fiat tappet or roller can do this easily but it’s an extra $1200 to go the roller route fir very little gain other than skipping the break in routine. If a block is roller ready then most just go that way.

Alot of the Old Mopars do HFT cams, they also survive with a conservative cam.

 

[skylark]

I personally would buy a 350 core engine with the factory roller cam. All 96+ vortec truck engines and a bunch of 87+ car engines (even tbi) have them. I would build a stroker and sell your current engine to offset your build costs. Don't bother with shortie headers, no gain there. Long tubes build torque. I would find a roller cam that has a bit more aggressive of a profile and I'd run full roller rockers. I like Scorpions because I've never had a set "tick" but Comp and Crane sure do.