400FWHP TBI build attempt thread

**Gojira94** · 02-20-2017

One more update, nothing exciting. I replaced the fuel pump with the EP381. Did the tank from the bottom after pretty much running it out of gas since it didn't have much in it when I got it, havn't put any in it since June 2016. I found the filler neck ground strap hanging loose (yikes). The fuel sender ground wire outside the tank was 2 pieces of wire with a wire nut and a lot of electrical tape around that (more yikes). Fuel line fittings at the tank are 19mm/16mm. I replaced the o-rings on the couplers on the tank side. BWD makes a pair for$3.99, BWD part # 27478, same as the Fuel line to TBI fittings o-rings, available at most parts stores. Observations/ conclusions- The pump has been obviously replaced before, found an Airtex E3902 inside the tank (stock replacement). The EP381 kit's rubber foot isn't qute a direct fit on the bottom support for the pump but holds fine when the strainer is on. I used a 50 micron strainer, Spectra A02STR. I capped everything on the tank once it was out and did a proper splice on the sending unit ground wire, with heat shrink sleeve and a proper connector on the end. The rear tank strap can be a real pain to get back in. The front one I just pulled the nuts for its bracket off the frame rail. I did all this on grass, lying on a sheet of cardboard, lol. To slide the tank out from under I just jacked the truck up by the diff and slid the tank out from the driver' side and used the same method to slide it back under, then lowered it again. I know a lot a folks are fans of doing the bed lift on the driver's side but I see no need for the trouble on a 2WD truck without all the extra shields a 4WD has.

I had issues with the dry 0-100psi gauge on the regulator. Wouldn't register anything, even with the 0-20psi spring in the regulator maxed out. I contacted the vendor and am awaiting a response. I bought the gauge in Late December. Their warranty is 30 days on everything, which I'd expect for their nitrous parts, but I'm hoping they'll pony up and do the right thing for a DOA gauge on first install. They have a great reputation on ls1tech so I'm cofident they'll be willing to help. Meantime I just grabbed a 0-15psi Mr. Gasket carb gauge and set it at 12psi running. Everything is good for fuel system to support the heads and cam swap, just need to be able to set pressure with the 20-60psi spring when the time comes. At worst I'll bite the bullet and get an Aeromotive wet gauge with the pressure relief button on it if I can't get help on the (dead) dry one.

I'm thinking about doing the exhaust and wideband next. The most it will cost me is a cheap pair of header gaskets to throw away when I do the top end work.

**Gojira94** · 04-21-2017

My world kind of blew up 3 days after the last update, not much of anything done for a while. Just wanted to say I haven't given up and I will be back with more updates in the next couple of months. Thanks to all who have had feedback and been helpful answering questions so far.

Thanks,

Rob

**Gojira94** · 04-21-2017

I did follow the advice of Dave W and Fast355 and bite the bullet and seek out a good pair of completely reconditioned, flow matched 80#/hr. injectors (5235231). The more I read about taking the 5235206 61#/hr. above 28-30psi the more I became convinced I needed to go bigger. So I'll be around 22-23psi on the 13301 regulator at WOT, much more comfortable with that. The only things I'm lacking at this point are time, a place to do the work and pushrods, lol. Though I do have a length checker for when the time comes.

Funny thing, I ran across a 94 LT1 F-body cam from a project back in 2009. Looks like it got some moisture exposure and has light rust in a couple places. I'll clean it up and post a pic, maybe someone can use it.

**Gojira94** · 05-22-2018

It's been a long time but I'm back with updates on this. I had the truck together and running pretty well. Something I overlooked in the cooling system stuck the thermostat on the way back from the beach here in NC and I blew a head gasket about 30 min from home. It limped home gamely and I parked it. A family friend who has a large shop on his farm invited me to do whatever work I needed to there so my problem of where to work has been solved.

I pulled the intake and this L05 has no hydraulic roller provisions whatsoever, so I ordered a .040 over 4 bolt main reman short block (880 'Vortec' block). The old engine was fitted with Fel-Pro 7733PT-2 .039" gaskets, heads look very fresh inside and out, almost no rust. The block is a 10054727. My guess is this is a low buck reman engine a PO had dropped in. I'll clean it up when it's out and see if I can find a VIN on it anywhere, out of curiosity. Right now I have 6 bolts to go before pulling it as a short block: 2 engine mount, top 2 trans bolts, 2 bolts for the oil cooler. My gut says keep the oil cooler and have the lines redone, rather than delete it or replace the lines with a pair of aftermarket ones. Opinions welcome on that. This truck will see some but not a lot of towing.

I'm reusing: knock sensor, OPSU and its stem, coolant temp sender in head, oil pan, timing cover, damper, flexplate.

New: timing set (12371043), LS7 lifters, 1.6 Summit stainless RRs, MH55 oil pump with welded pickup & new dist shaft.

Full list of other new parts I'll update later but includes Promaxx 2169 heads set up for HR cam, Comp 08-422-8 cam, Mahle 5746 head gaskets (Nitroseal, .026, 4.125) instead of the .015 shims I had planned on with the -12.3cc dished pistons in the old L05. New short block has -6.7cc slugs .025 in the hole.

Static CR I've calculated at 9.93:1 and DCR 8.16:1. Since I'm running the EBL Flash ECM I figure I can create a tune very conservative on timing for 87 octane if I really want to and another for 91 octane and maybe yet another slightly more aggressive if I want to run some 93 and milk a couple more degrees here and there.

I'll post some pics and add pics back to some earlier posts. What I need to focus on fairly soon is getting some feedback on the new VE tables I created a while back as well as get a timing table put together for first startup. I'll likely try using the 61pph injectors for first startup so as not to deal with rich issues trying to seat the rings. They should be able to deliver enough up at around 17-18psi to get to 4500RPM safely for engine braking segments of the ring seating.

Back within a couple days with what I have in EBL Flash. It's good to be back. :)

**Fast355** · 05-23-2018

Originally Posted by Gojira94

It's been a long time but I'm back with updates on this. I had the truck together and running pretty well. Something I overlooked in the cooling system stuck the thermostat on the way back from the beach here in NC and I blew a head gasket about 30 min from home. It limped home gamely and I parked it. A family friend who has a large shop on his farm invited me to do whatever work I needed to there so my problem of where to work has been solved.

I pulled the intake and this L05 has no hydraulic roller provisions whatsoever, so I ordered a .040 over 4 bolt main reman short block (880 'Vortec' block). The old engine was fitted with Fel-Pro 7733PT-2 .039" gaskets, heads look very fresh inside and out, almost no rust. The block is a 10054727. My guess is this is a low buck reman engine a PO had dropped in. I'll clean it up when it's out and see if I can find a VIN on it anywhere, out of curiosity. Right now I have 6 bolts to go before pulling it as a short block: 2 engine mount, top 2 trans bolts, 2 bolts for the oil cooler. My gut says keep the oil cooler and have the lines redone, rather than delete it or replace the lines with a pair of aftermarket ones. Opinions welcome on that. This truck will see some but not a lot of towing.

I'm reusing: knock sensor, OPSU and its stem, coolant temp sender in head, oil pan, timing cover, damper, flexplate.

New: timing set (12371043), LS7 lifters, 1.6 Summit stainless RRs, MH55 oil pump with welded pickup & new dist shaft.

Full list of other new parts I'll update later but includes Promaxx 2169 heads set up for HR cam, Comp 08-422-8 cam, Mahle 5746 head gaskets (Nitroseal, .026, 4.125) instead of the .015 shims I had planned on with the -12.3cc dished pistons in the old L05. New short block has -6.7cc slugs .025 in the hole.

Static CR I've calculated at 9.93:1 and DCR 8.16:1. Since I'm running the EBL Flash ECM I figure I can create a tune very conservative on timing for 87 octane if I really want to and another for 91 octane and maybe yet another slightly more aggressive if I want to run some 93 and milk a couple more degrees here and there.

I'll post some pics and add pics back to some earlier posts. What I need to focus on fairly soon is getting some feedback on the new VE tables I created a while back as well as get a timing table put together for first startup. I'll likely try using the 61pph injectors for first startup so as not to deal with rich issues trying to seat the rings. They should be able to deliver enough up at around 17-18psi to get to 4500RPM safely for engine braking segments of the ring seating.

Back within a couple days with what I have in EBL Flash. It's good to be back. :)

Very similar to what I am working with in the Express van. I kept the 12cc factory pistons though. Assault racing 205cc heads I bought bare and built. Custom grind 215/224 @ .050 comp cam on a 110 LSA. Scropion 1.7 roller rockers. 0.568/0.568 lift. GM 0.28" compressed head gaskets. LS7 lifters, comp magnum pushrods, 5/16 guide plates, 7/16 stud, high pressure standard volume mellings 454 oil pump, mildon windage tray. I am actually tearing the upper end down this weekend again for a TPI top end. I have been wanting to swap out the marine intake for the TPI intake for some time. Ported Edelbrock 3817 Vortec TPI base, siamese ported SLP runners, ported plenum and a 58mm LT1 throttle body.

**Gojira94** · 05-23-2018

Originally Posted by Fast355

Very similar to what I am working with in the Express van. I kept the 12cc factory pistons though. Assault racing 205cc heads I bought bare and built. Custom grind 215/224 @ .050 comp cam on a 110 LSA. Scropion 1.7 roller rockers. 0.568/0.568 lift. GM 0.28" compressed head gaskets. LS7 lifters, comp magnum pushrods, 5/16 guide plates, 7/16 stud, high pressure standard volume mellings 454 oil pump, mildon windage tray. I am actually tearing the upper end down this weekend again for a TPI top end. I have been wanting to swap out the marine intake for the TPI intake for some time. Ported Edelbrock 3817 Vortec TPI base, siamese ported SLP runners, ported plenum and a 58mm LT1 throttle body.

That will be one fun van... is your block decked? The best I could come up with on my old block or another offering where I got my SB, both with -12.3cc dish, was a hair over 9:1 with the 7733SH-1 shims or almost 8.9:1 with the .028GM 4.1 bore gasket. That would have been very 87 friendly but would have given me a quench of over .070 with pistons .025 in the hole. IMHO reman short blocks should be decked and finished to .012 - .015 in the hole for flexibility either way and put quench range between .035 - .050 max. My quench will be a little looser than I'd find ideal but should be ok at .051. Most GM crate engines have quench looser than that with no detonation issues on 87.

Your cam has me intrigued. What's the IVC ABDC? Wondering what kind of DCR that cam gives and what dynamic cranking pressure would be. I calculated my DCP at 162.22PSI. Good thing to know when doing a compression test down the road some day.

**Fast355** · 05-23-2018

Originally Posted by Gojira94

That will be one fun van... is your block decked? The best I could come up with on my old block or another offering where I got my SB, both with -12.3cc dish, was a hair over 9:1 with the 7733SH-1 shims or almost 8.9:1 with the .028GM 4.1 bore gasket. That would have been very 87 friendly but would have given me a quench of over .070 with pistons .025 in the hole. IMHO reman short blocks should be decked and finished to .012 - .015 in the hole for flexibility either way and put quench range between .035 - .050 max. My quench will be a little looser than I'd find ideal but should be ok at .051. Most GM crate engines have quench looser than that with no detonation issues on 87.

Your cam has me intrigued. What's the IVC ABDC? Wondering what kind of DCR that cam gives and what dynamic cranking pressure would be. I calculated my DCP at 162.22PSI. Good thing to know when doing a compression test down the road some day.

Block is a stock deck, 2005ish GM 1-ton Vortec 350 crate engine. Hecho en Mexico. Where are you calculating your quench from? The top of the piston recess? My pistons are 0.025" down. The GM ZZ4 and 330 HP 350 HO ran 0.051" compressed head gaskets when they were built. The ZZ4 had flat tops and L98 aluminum heads and the 330 hp 12cc dished with Vortecs. I feel the slight compression difference advertised between the factory Vortec engine and the 330 HP crate is due to the head gasket.

**Gojira94** · 05-23-2018

Also, I'm using the Holley 300-49 intake and have worked out all the bracket stuff using stock brackets with a slight bench grinder shave in a couple of spots. More on that with pictures as well. Throttle body is a worked 46mm unit from dctrumpet on TGO. Also using a 1" spacer from Jegs and the salad bowl.