Ok so what do u think guys should I go with a 350 tpi or a 350 lt1 what would be my best bet for the 400hp range im trying to get to tell me the goods and bads about both engines right now I have a 305 ho 5.0 in my 89 camaro irocz and everybody telling me to just throw away that engine cause it aint no good is that true or not thanks

 

Your best bet for 400 crank horsepower is a 383 LT1.

 

well for one thing the TPI system is very constricted. It gives great low end torque.. but after about 4500rpm it runs out of power drastically. I have no experience with the LT1 but I think they're a little better with keeping the power curve on track but i could be wrong.
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For my L98 I'm building a Holley Stealth Ram setup soon, Honestly the best Efi system out there for HP and TQ. And makes it an ease to work on the motor (With the TPI the runners get in the way making it a pain to work). The Holley Stealth Ram setup among other mods would easily reach your 400hp goal. If you start with a 350TPI motor you won't need the entire HSR Set up just the Manifold, Plenum, Fuel Rails and a 58mm TB. About 900$ total for the unpolished and around $1200 for the polished version. But it is a great mod that will bring a ton of power, and pretty up the engine bay something fierce. As i said you'd definitely reach your 400hp goal with the HSR, Though it is pretty expensive way to go. Also something to think about are AFR 195cc Heads, They've proven to give many times a 90hp gain on the stock L98 block, Those are about 1400$ plus shipping. I would also suggest looking into the Dyno Don Custom Headers&Y-Pipe Kit you can buy from Dyno Don on these forums, they're the best available for our cars with the best power results and ease of install.
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This is a member's HSR setup bayhis forum name is "IROCThe5.7L". His engine bay and all the info I've found on these forums and others made me want to go the HSR route.

 

Yea slash I lik that hsr setup thats bad *** imma have to really look into that and u say it cost around 900

 

You have to realize though it's $900 but adding the HSR wont give you 100hp it will just make it possible to get there. You would still need high flowing heads, headers and everything that goes into it like gasket's and little nickle and dime crap.....in the end to get a 400hp TPI will cost around $4000 pretty much what a 400hp LT1 will just because of the motor's and part's you need to make both of them get that power.

It depend's what you find and how deep your pocket's are, I wanted and LS swap but it's too much money so Im just going to mildly build my TPI and maybe add a 75-100 shot of NOS.

 

I'd get a vortec 350 from a 96 up truck, the vortec heads have the air flow & combustion chamber designed after the lt1 heads. Stroke that & use a different type of intake, tpi intakes are tuned to make hp at lower rpms.
I'd avoid the lt1 b/c of the stupid distributor & reverse flow cooling system that you would have to adapt. Nobody swaps lts anymore, they use the ls engines (10 years ago they would have used lt1 in a swap) b/c there a good value.

 

Buy the whole car, grab what you want. Part out the rest
http://memphis.craigslist.org/cto/2429053626.html

 

The HSR system alone has been proven to give around a 70hp increase over the stock TPI system on the L98s(The HSR is the best of the EFI systems out there, Followed by the mini ram, T-Ram, Super ram). Afr 195cc heads have been proven time and time again on dyno sheets on these forums to give a 90hp increase on a stock internal L98. (Note we're talking at the crank here, not at the rear wheels) 900$ for HSR(+ some doodads i can't thinks of atm), 1500$ for the Afr 195 Heads. Lookin at about 128hp added at the wheels going by the .2 loss from crank to wheels.

 

If you can find a complete LT1 in decent condition, then just throw a CC306 cam in it with headers/exhaust and a mail order tune and be done with it. thats over 400 crank hp...350whp.

If you went 350 small block like an L98, you'd need to upgrade heads/cam/intake to make 400 crank hp, so the LT1 in the end could be cheaper swap.

 

Where can I buy the hsr kit from slash

 

summit racing has them. You can get intake/rails and fuel lines for about 600-650 if you shop around. TB is another 200-300 bucks which is not needed for 400hp to be honest. Just keep the stock 48mm TPI unit.

HSR is a nice intake, extends stock L98 powerband from 4200-4400 to peak near 5000-5200 and holds ok til 5500 but its dropping off after that pretty hard. They advertised 50-70 hp on stock motor but thats comparing power at 5500 ish rpm where TPI is so far off its powerband its not even funny. It all helps tho if you factor in area under the curve, but TPI requires different shift points compared to HSR.

HSR on stock L98 with tune may only make 20hp more at peak but its still a significant improvement. You will notice alot faster ET's at the 1/4 mile. I've been there done that with the HSR on bolt on L98s.

AFR heads on stock internal L98 with stock cam may only gain 30-40hp with a good intake on top, not 90+ hp unless your looking at way past TPI peak compared to a short runner intake like miniram/HSR. Even 30-40 peak is optimistic with stock cam..simply too small of a cam to make big gains, but thats the best I've seen posted and only know of one person who did that test on stock internal motor. Not many do heads only as it doesnt make much sense.

Now if you compared a cammed stock headed motor to an aftermarket high flowing head and that same cam, you may make 90 hp more. All depends on the setup.

 

It's technically called "Weiland Stealth Ram" now

http://www.summitracing.com/parts/WND-7540/ - 330$ manifold&plenum

http://www.summitracing.com/parts/HLY-534-185/ - 185$ fuel rails

http://www.summitracing.com/parts/HLY-112-503/?rtype=10 - 355$ 58mm throttle body(suggested but not needed)

 

Aw ok so thats why wen I was lookin for it I couldnt find it but this is something I wanna know if I buy the bolt ons for the 305 tpi I have now lik heads, header, intake, manifoid, cam and stuff lik that wen I do find a l98 tpi 350 would those same parts for the 305 work fine for the 350

 

Most parts that bolt onto the 305 will bolt up with the 350 aswell. I honestly wouldn't put money into a 305, it takes tons to make them even equal a 350. Save up buy a 350, an engine stand and build it while ur driving the stock 305. then once the 350 is finished transplant it

 

Although the best budget option for quik power...theres no way a cam only cc306 lt1 is putting out 400 hp. I have a cc306 lt1 with headers, ignition, ported heads ect ect and I would guess its around 350 max. cc306 is an amazing cam, but there are better out now that will get a little more low end back and keep the top. the cc306 revs out like theres no tomorrow but it doesnt have a ton of low end.

a ported lt1 383 would get you where you want to be.

 

I am refering to 400 crank hp not wheel hp. Cam only LT1's are 350whp and some as high as 370whp depending on the tune/exhaust mods/etc. Thats easily 400 at the flywheel. I can show you dozens of vids/dyno threads on cc306 cam only LT1's making 350+ at the tires. If your not, then something is seriously wrong

 

Not for arguments sake, but for curiosity I would like to see them.

 

http://www.ls1tech.com/forums/lt1-lt...only-dyno.html

theres a few in that thread, 340-370whp depending on the setup

http://www.youtube.com/watch?v=9_lXvESyDY8
12.4 at 114 cc306 cam only car
Heres his dyno 366whp/368wtq
http://www.youtube.com/watch?v=D7old...feature=fvwrel

Heres a smaller cam only 224/236 car....374whp though a Th350, stock LT1 heads
http://www.youtube.com/watch?v=3sHsc...eature=related

This one used XE comp grind 230/236 and made 340whp
http://www.youtube.com/watch?v=4HQq2y_mJ6A

heres a cc503 grind 224/230 that made 332 which is abit low for that cam. Usually in the 340-350 range too but he has just a mail order tune
http://www.youtube.com/watch?v=I1Q6e...eature=related

Theres a lot out there that i have seen that I just dont have links to anymore. When I was doing LT1 intake conversion for my L98, I was gonna do a set of mild ported L98 heads and cc306 cam or the xe 230/236. I expected 350whp atleast. Never went through with it but want to try again someday with stock L98 heads to see what I can get cam only