one92rs

iTrader: (5)

now it is time to replace my low oil pressure put up wet 305. I have a 350 engine in the garage from a 91 caprice wagon. tbi. what I got was the long block. in good shape. going to get the machine work done on the bottom end. .30 over and 10-10 on the crank. now I am kinda stuck on the heads. want a good running engine. have the 193 heads from the engine. I also have an lt1 cam on hand. don't want to go completely wild either. wanting in the 300hp range.
what I have
1. 1991 lo5 350 long block needs rebuilt .30 over and 10-10 crank.
2. 193 lo5 heads need gone thru
3. lt1 cam

ideas and maybe's.
1. better heads----vortec, port mine, edelbrock, afr???????????????????????
2. better cam----????????????????????
3. which tbi will I need 350 stocker or bigger

mods on car
1. hooker shorty headers and ypipe
2. hp cat
3. magnaflow catback
4. ultimate tbi mods
5. built trans-----400hp 400 tq capabilities.

again thinking 300hp range. don't need egr for visual. but maybe to help pass sniffer.

any and all ideas wanted. even the smallest ideas can be the biggest contributors. please tell all.

Schurkey

The Caprice LO5 is an excellent starting point for a mild 5.7-based engine. I have the crate version in my K1500 truck. As installed in the Caprice, you'd already have enough compression for 300+ horsepower. Rods and crank are up to the task. Hydraulic roller cam is standard, but pathetically mild. You're stuck using an electric fuel pump. The exception to the joy is the cylinder heads which are low-performance junk. The original intake manifold is no treasure, but you don't have that anyway.

Have you checked the cylinder walls for wear/taper? Have you inspected the crank? You said this long-block was in good shape. Why does it need to be bored and ground?

The swirl-port heads are good paperweights. Fine for low-performance use, useless for upgrading.

I would install aftermarket cylinder heads that had a non-vortec bolt pattern and did have an exhaust crossover. This gives you a wide range of aftermarket intake manifold options including some with EGR passages. Use a 454 TBI-to-Q-Jet adapter. This assumes that you have hood clearance sufficient for the manifold and the adapter. For fukk sakes, don't waste money on an open-element air cleaner, or some junk cone-filter "cold air intake".

A 350 TBI should be good to 300 hp IF YOU CAN TUNE THE COMPUTER and have reasonable fuel pressure. 'Course, if you can do the tune, the 454-sized TBI is an option.

The main reason the LT1 cams are a popular swap is because they're cheap. It's not like they're all that special from a performance perspective. OTOH, you already own it, and it sure beats the original TBI cam.

Building the engine for 300 hp is no problem. Tuning the computer will be way more difficult than prepping the engine.

thomas1976

Personally I would take the 193 heads and LT1 cam off the build list, if possible.

one92rs

iTrader: (5)

my car is tbi now. so I have a lot of the parts.

1. rebuild. yes. because I am only doing this once. if it is going in like everything else it will be either new or rebuilt. DO IT RIGHT AND DO IT ONCE.

2. heads?????? I can go to new heads. no problem. WHICH ONES.
I have looked at different heads but im not the head connoiseure. if I need better ones I have tried to set aside about $800.00 for the heads if needed.

3. cam???? give me a spec that will work and I can do that. I cant tune but EAGLEMARK can. he has tuned my car and im sure he is very capable of doing it again.

4. thought of going to the edelbrock tbi since I can retain the egr for 2 more years.

5. like stated above the exhaust I have now should be sufficient.

tbi??? thought about going with a bored cfm tech tb if needed.

thomas1976

With the engine disassembled, check if machining is necessary, if not necessary and it has these pistons https://www.thirdgen.org/forums/atta...91-5.7-gta-o.e. you may have the chance to save some money on the short block.

Carcraft has published an article with the budget aftermarked heads not too long ago https://www.thirdgen.org/forums/post...21-post24.html

one92rs

iTrader: (5)

it does have those pistons. 123000 miles to be exact.

one92rs

iTrader: (5)

not sure if my eyes are deceiving me. but the dart heads seem to be the only ones with the port for egr.

thomas1976

That is a decent short block you have there, check if out of round of the bores are within specs.

Summitracing 170 heads have EGR port and the Edelbrock should have them with EGR port too.

mrdoke

I have just converted my 383 stroker to the new holly terminator!
I HAVE A NEW BORED OUT GM TBI WITH MATCHED 454 INJECTORS AND A HOT CHIP MADE FOR THIS tbi FROM hARRIS PERFORMANCE I ALSO HAVE A MSD REPLACMENT DISTRIBUTOR FOR THE STOCK COMPUTER ALL ALMOST NEW (I WANTED OVER 400 HP) THIS SETUP MADE 300 HP WITH A MILD STREET CAM AND VORTEC HEADS ALL CAN BE YOURS FOR 350.00

one92rs

iTrader: (5)

here is a set of heads that summit says is for 87 and up small blocks. they look good.
http://www.summitracing.com/parts/sum-162108/overview/

mrdoke-- that sounds like a really good idea. the money I have coming in isn't here yet. so I am sure you will have sold all that. that would include the tbi, dizzy, and chip correct.

1991sleeper

iTrader: (-3)

I am currently running g TBI with the EBL flash for tunning ... even tho mine is a 305 I'm running 350 HP ... I used cFM techs 620cfm TBI ,blocked off the factory pressure regulator and used an aeromotive vacuum reference regulator , 68# injectors @ 30psi fuel pressure .... I'm using a Howard's cam 214/218@.050 .488/.495 lift on a 114 LSA , flat top pistons and trickflow 175cc heads and get 24mpg with 4:10 years and a T5 .. cam is very streetable too

91' bird 305 TBI T-5, trick flow 175 cc heads, 4.10 gears, lots of suspension upgrades. 24mpg @ 2500rpm hwy. 8.80@ 84mph 1/8th on street tires... 8.000's soon

thomas1976

If you want a in depth overwiev https://www.thirdgen.org/forums/tech...ml#post5446621

89-S-dime

iTrader: (3)

Brian from Harris performance made you a chip for your TBI with vortec heads? and it ran good?

one92rs

iTrader: (5)

wow thomas1976. thanks for the info. so you did do what all you could to clean up the heads. will do the same here. now do you wish you had gone to a different cam? or do you like the one you have. I seen atilla mentioned another cam in the posts.

thomas1976

I'm happy with the 8-500, though the 8-501 has a little more lift and duration and I have not tried it.
At the time of the build I was aiming for a mild engine to use with a low stall converter and the engine simulators were showing the 8-500 among the cams that make the best power under 5500 rpm.
I also ended up porting the 3704 and that made a noticeable difference.

one92rs

iTrader: (5)

cool. did you port just the tbi holes to 2" or did you gasket port it to.

thomas1976

Here are some pics https://www.thirdgen.org/forums/tbi/...bi-3704-a.html

one92rs

iTrader: (5)

I have read all that you have given me. thanks!!!!!!!! are you running a flat tappet cam or roller. when I punch in the number I get a summit flat tappet. I have been looking at a comp cam.

Camshaft Specification Table
Part Number 08-422-8
Engine -9999 Chevrolet
305ci-350ci
8cyl.
Grind Number CS XR270HR-10
Description
Intake Exhaust
Valve Adjustment 0 0
Gross Valve Lift 0.495 0.502
Duration At 0.006 Tappet Lift 270 276
Valve Timing At 0.006
Open Close
Intake 29 61
Exhaust 72 24
These Specs Are For The Cam Installed At 106 Intake CL
Intake Exhaust
Duration At 0.05 218 224
Lobe Lift 0.33 0.335
Lobe Separation 110
Recommended Valve Springs 986-16

1991sleeper

iTrader: (-3)

If ur gonna keep TBI go with about a 112 LSA .. Unless someone else is gonna tune it for u ... I went with 114... And I get decent mpg good vacuum decent idle and wide power band.....

The can u listed above will perform about the same in a 350 as my 214/218 can does. in my 305 ... Seems like power stats to drop off around 6k so that's where I shift.. But I'm also running 1.6rr so my lift is .520/.528

91' bird 305 TBI T-5, trick flow 175 cc heads, 4.10 gears, lots of suspension upgrades. 24mpg @ 2500rpm hwy. 8.80@ 84mph 1/8th on street tires... 8.000's soon

thomas1976

The 8-500 and 8-501 are both roller cams.
http://www.compcams.com/Company/CC/c...?csid=193&sb=0
http://www.compcams.com/Company/CC/c...?csid=194&sb=0

one92rs

iTrader: (5)

here is what comp cam said to use. Thomas u nailed it!!!!!!!!!

08-501-8 XR264HR

1200 TO 5200

.006 valve timing

lobe sep----112*

int. centerline---108*

dur--264 269

@50 212 218

lift .488 .495

lift .325 .330