TylerZ281500
Yukon Ridin High
305 vortec heads dont carry the superiority of 350 vortec heads, theres no benefit swithcing them out. if you want a better head for a 305 id look into 416 and drill for the added serp bracket holes, run a regular carb intake and a carb to tbi adapter.
350 heads on a 305 would have to be shrouded, a 350s bore is larger than the bore of a 305, the 350 head will have a larger chamber in this case that the block of a 305 thus shrouding or whatever other term you care to use.
head shaving depends on CR and how many cc the chamber on the heads are. if you have a -.012 piston with .025 quench running a 70cc head and and .045 compressed gasket thickness youll have like 7.8:1 compression at the most which is god aweful not knock say .010 off that 70cc head you could get around 60 which can plausibly bump your compression to say 9.2. those are very rough numbers but you get the idea.
if you have a 305 i wouldnt waste much on it. tbi excels on 350s mods work nicely with 350s as much as i love 305s they really have an ill place in a truck. do the basics id say, heads cam intake exhaust and dont forget to tune it, if your not gonna tune it then i wouldnt touch any part of it.
ive never dealt with a tbi 305 but there many builds on thirdgen.org unfortunately you are a truck so i would personally run a 416 head, studded, ls6 springs, stock lt1 cam with 1.6's a carb intake, i run a single plane n my 350 tbi id do the same in hopes that it would react the same, otherwise if we are worried about smaller engine volume then stick with a dual plane, shorty headers, dual exhaust with x or h pipe and a good muffler will net you the best possible hp
as far as fueling, ultimate tbi mods, once again havent messed with 305 tb's so id have to measure and look at injector rates but id honestly mod a 350 tb and slap it on there without pressure bump. 350 injector should flow more lb/hr and be beneficial to a slight modded 305. ill look into it tomorrow. then tune it! tuning is key, tbi works at 100% effieciency or 0% pick which one youd like. for better info on tuning go to gearhead efi.com or if you want it done hit up one of the fellows on there someones bound to give you a good base tune for cheap. e fans are a good mod, if your planning on a 350 in the future you can change your fuel pump out to a vortec unit with a earomotive 13301 VAFPR on your return line.
Keep your EGR you can delete smog but your egr is beneficial when dealing with TBI, i shouldve left mine on.
SMOG you can delete i guess, screw it.
3 wire heated o2 bosch number 13077 or delco afs74 also a benefical mod for any tbi powered vehicle, helps you get into closed loop quicker so your conserving a bit of mileage and get into power sooner.
are you auto or stick? trans mods would be next shift kit, stall servos, cooler, external filter
magnefine for filter, any CLEAN external cooler would be beneifical, transgo for your shift kit, stock vette servo should give you a nice 1-2 shift off the line.
as far as stall if your 4wd you want something on the tighter side, regardless a cheap alternative are the 4.3 converters stalling around 2200 behind a 4.3 and 1650 behind a 350. conservatively we will say that it should net you around 1800 behind a 305 (just a guess) now all together thatd go very nicley with that lt1 cam and put your power range right where you should be assuming a 3.42 gear. 3.73 would more than likely wake the entire truck up even further depending on your tire size.
lost? any questions? sadly enough i have everything i just mentioned in my garage, looks like i should build a 305 truck
350 heads on a 305 would have to be shrouded, a 350s bore is larger than the bore of a 305, the 350 head will have a larger chamber in this case that the block of a 305 thus shrouding or whatever other term you care to use.
head shaving depends on CR and how many cc the chamber on the heads are. if you have a -.012 piston with .025 quench running a 70cc head and and .045 compressed gasket thickness youll have like 7.8:1 compression at the most which is god aweful not knock say .010 off that 70cc head you could get around 60 which can plausibly bump your compression to say 9.2. those are very rough numbers but you get the idea.
if you have a 305 i wouldnt waste much on it. tbi excels on 350s mods work nicely with 350s as much as i love 305s they really have an ill place in a truck. do the basics id say, heads cam intake exhaust and dont forget to tune it, if your not gonna tune it then i wouldnt touch any part of it.
ive never dealt with a tbi 305 but there many builds on thirdgen.org unfortunately you are a truck so i would personally run a 416 head, studded, ls6 springs, stock lt1 cam with 1.6's a carb intake, i run a single plane n my 350 tbi id do the same in hopes that it would react the same, otherwise if we are worried about smaller engine volume then stick with a dual plane, shorty headers, dual exhaust with x or h pipe and a good muffler will net you the best possible hp
as far as fueling, ultimate tbi mods, once again havent messed with 305 tb's so id have to measure and look at injector rates but id honestly mod a 350 tb and slap it on there without pressure bump. 350 injector should flow more lb/hr and be beneficial to a slight modded 305. ill look into it tomorrow. then tune it! tuning is key, tbi works at 100% effieciency or 0% pick which one youd like. for better info on tuning go to gearhead efi.com or if you want it done hit up one of the fellows on there someones bound to give you a good base tune for cheap. e fans are a good mod, if your planning on a 350 in the future you can change your fuel pump out to a vortec unit with a earomotive 13301 VAFPR on your return line.
Keep your EGR you can delete smog but your egr is beneficial when dealing with TBI, i shouldve left mine on.
SMOG you can delete i guess, screw it.
3 wire heated o2 bosch number 13077 or delco afs74 also a benefical mod for any tbi powered vehicle, helps you get into closed loop quicker so your conserving a bit of mileage and get into power sooner.
are you auto or stick? trans mods would be next shift kit, stall servos, cooler, external filter
magnefine for filter, any CLEAN external cooler would be beneifical, transgo for your shift kit, stock vette servo should give you a nice 1-2 shift off the line.
as far as stall if your 4wd you want something on the tighter side, regardless a cheap alternative are the 4.3 converters stalling around 2200 behind a 4.3 and 1650 behind a 350. conservatively we will say that it should net you around 1800 behind a 305 (just a guess) now all together thatd go very nicley with that lt1 cam and put your power range right where you should be assuming a 3.42 gear. 3.73 would more than likely wake the entire truck up even further depending on your tire size.
lost? any questions? sadly enough i have everything i just mentioned in my garage, looks like i should build a 305 truck
