without pulling trouble codes and testing your simply guessing at best,
break the issue down into separate issues,
check ignition strength and timing,and voltage
check fuel supply/delivery pressure and volume
check cam timing and cylinder compression.
check valve train control and valve adjustment
check firing order and spark plug gap
check the valve lift, and for work lobes
check for vacuum leaks
adjust your iac and tps
check your exhaust back
pressure
verify sensors correct function
https://www.harborfreight.com/11-piece-noid-light-and-iac-tester-set-97959.html
https://www.jegs.com/i/JEGS/555/W89...MIoLGlpLnz3gIVDFYNCh36aAK4EAQYAiABEgKTIvD_BwE
what goes in needs to exit with minimal flow restriction, an (X) pipe and dual 3" exhaust helps
all the answers are readily available, theres known testing procedures and listed test results you can expect, and procedures listed in the shop manual for isolating and testing components, you don,t need to be a genius, you just need to be logical and persistent and not afraid to learn new things while getting your hands dirty at times, don,t get overwhelmed , break everything down too easy individual problems and tests, verify and test all the sensors,and test for factors like consistent fuel pressure, known temps,expected voltage or ohms resistance, and vacuum readings and don,t randomly start replacing parts as that gets expensive and its rarely the most efficient way to eliminate problems(unless you get really lucky) with modern computer diagnostic software you,ll have some advantages but think logically, most automotive problems still concern, loose electrical connectors, defective sensors, lack of compression, fuel delivery issues ,fuel pressure, vacuum, temperature or electrical issues.
http://www.helminc.com/helm
you might have clogged catalytic converters, the ignition timing may be way off, you might have a worn out cam, the fuel pump may be defective, some injector(s) may be defective,check the alternator out-put check the fuel rail pressure use a noid light on the injector wiring, check the fuses,
Ive found that the one most commonly over looked in my experience is that the stock exhaust system, is highly restrictive, especially if the catalytic converters are partly plugged and the stock fuel delivery system is not adequate,for the potential power, the heads and intake, allowable air flow potential, are all restrictive, and the stock cam timing and lift is already near max as it was designed to produce about 260 hp,and operate at under 5700 rpm, if you try too add an additional 100-200 hp, and 1000 rpm-2000 rpm to the engines power band, and too the engines output youll quickly find this to be a factor.
I've also occasionally seen guys, improperly index or install a cam without degreeing it in correctly and thus have power band limitations.
Id suggest you buy a factory shop manual, multi meter and a timing light, fuel pressure and vacuum gauge and start checking.
the CASTING #642 cross fire heads and even most fuelie heads, and all the TPI heads, are compared to today's better designed cylinder heads... well pathetically restricted,
I would strongly suggest you select an aluminum cylinder head (with at least a 190cc and 200 cc port is better in most cases,that flows a MINIMUM of 250 cfm at .500 lift)
TRICKFLOW
http://www.trickflow.com/egnsearch.asp? ... 4294867081
http://www.trickflow.com/customerservice
1-330-630-1555 • 1-888-841-6556
BRODIX
http://www.brodix.com/heads/heads.html
479.394.1075
DART
http://www.dartheads.com/products/cylinder-heads
Dart Machinery; 248/362-1188; DartHeads.com
AIR FLOW RESEARCH
http://www.airflowresearch.com/
toll free: 877-892-8844
tel: 661-257-8124
Patriot Performance
Patriot Performance; 888/462-8276; Patriot-Performance.com
RHS
http://www.racingheadservice.com/rhs/cylinder-headshtml
Toll Free: 877-776-4323
Local: 901-259-1134
EDELBROCK
http://www.edelbrock.com/automotive_new ... main.shtml
Edelbrock; 310/781-2222; Edelbrock.com
BMP (world products)
http://www.theengineshop.com/products/cylinder-heads
Tel: 631-737-0372
Fax: 631-737-0467
BUTLER PERFORMANCE
http://www.butlerperformance.com/products/cylinder_heads/cylinder_head_labor.html
866-762-7527
BLUE PRINT ENGINES
http://www.blueprintengines.com/ind...sb-chevy-aluminum-cylinder-heads-cnc-machined
1800-483-4263
PRO-FILER
https://www.profilerperformance.com/
937‐846‐1333
YOU CAN BUILD A tpi BASED ENGINE ON THE ORIGINAL LOW COMPRESSION 350 SHORT BLOCK BUT THERES POTENTIALLY A VERY GOOD BOOST IN POWER AND TORQUE IF YOU INCREASE THE DISPLACEMENT TO 383-406 AND INCREASE THE COMPRESSION TO THE 9.5:1-10.2:1 RANGE.
the intake selected should be port matched and if possible ported to maximize flow
the FIRST TUNED PORT intake provides exceptional results
- FIRST TPI Intake.(good choice)
intake comes with a new throttle body
if matched to a cam and cylinder heads and a low restriction set of headers and exhaust, that allows it to breath.
the crane 119661 roller cam works rather well, on a brisk street performance build (especially with a wet nitrous TPI set up) even more power is available with the crower 00471 roller cam or crane 119651 roller cam
all three performance hydraulic roller cams will require a 3000 rpm-3200 rpm stall converter and are best matched to a 3.73:1 REAR GEAR RATIO
http://garage.grumpysperformance.com/index.php?threads/ideal-tpi-build.12203/#post-76070
http://garage.grumpysperformance.co...-stock-tpi-engine-components.1509/#post-74581
http://garage.grumpysperformance.co...rger-intake-runners-l98-tpi.13785/#post-72541
http://garage.grumpysperformance.co...lay-switch-locations-and-info.728/#post-66935
http://garage.grumpysperformance.co...intake-for-cross-fires.2796/page-7#post-56659
http://garage.grumpysperformance.co...8mm-throttle-body-on-your-tpi.290/#post-54181
http://garage.grumpysperformance.co...ps-on-building-a-tpi-383-c4.10434/#post-51507
http://garage.grumpysperformance.com/index.php?threads/can-you-get-there-with-tpi.10494/#post-44299
http://garage.grumpysperformance.com/index.php?threads/tpi-flow-info.10382/#post-43474
http://garage.grumpysperformance.co...m-dyno-results-and-other-info.433/#post-37683
http://garage.grumpysperformance.co...y-current-corvettes-383-combo.430/#post-32660
don,t skip reading the links and sub links
http://garage.grumpysperformance.co...lay-switch-locations-and-info.728/#post-54562
http://garage.grumpysperformance.co...w-cam-now-engines-burning-a-bit-of-oil.14569/
http://garage.grumpysperformance.com/index.php?threads/code-scanners-software.3096/#post-76215
http://garage.grumpysperformance.co...tten-egg-smell-eyes-iritated.2813/#post-13444
http://garage.grumpysperformance.co...questions-can-be-found-here.12892/#post-67808
http://garage.grumpysperformance.co...-won-t-start-intermittently.14212/#post-72158
http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/
http://garage.grumpysperformance.com/index.php?threads/is-backpressure-hurting-your-combo.495/
http://garage.grumpysperformance.co...ive-are-the-stock-tpi-engine-components.1509/
http://garage.grumpysperformance.com/index.php?threads/how-big-a-fuel-pump-do-you-need.1939/
http://garage.grumpysperformance.com/index.php?threads/calculate-fuel-injector-size.1200/
http://garage.grumpysperformance.com/index.php?threads/adjusting-your-tps-and-iac.168/
http://garage.grumpysperformance.com/index.php?threads/c4-c5-corvette-trouble-codes.2697/
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