Hi all. Been lurking for a while and joined up the other day. I have a planned project and wondered if I had any fatal flaws in my plan. Any and all suggestions welcome as I am new to building TBI equipped vehicles (somewhat as I have a Howell GM inj 383 in my CJ8 << but that was prepped for me by Howell). This motor will be placed in my 1994 FS Blazer/4L60E 4x4. Trying to keep the budget on the lesser is better side......projects almost never go that way.... :)

My Plan: a 400 sbc and my usage is a TQ'y truck/tow motor. RPM range most used idle to 3500rpm's...wouldn't mind a blast to 4500-5000 occasionally but that is not a requirement and maybe not likely given my desire to stick with the 193's and low rpm goals.

I have been sitting on a 400sbc (would consider just doing similar things to a 383) as I love the TQ potential of 400's
It'll be built with 5.7" rods, I would make it easy and go with 5.565" rods (lets not get into long vs. short rod thing, in this application I don't believe it'll make any difference) but I find it near impossible to find (5.565") pistons that'll give a reasonable comp ratio with 65cc 193's. So......

400 .030, 5.7" rods, and looking at KB126 pistons 30cc D dish hypers (9:1 w/64cc). Still need to measure deck height as they vary (can be quite a bit) and deck as needed. I will shoot for a good quench and try for mid 9:1 comp ratio if possible. I want to stay with 193's for their good low rpm TQ potential and minimal headaches and EGR compatibility and intake coolant heating. Correct me if I am wrong that EGR can be a good thing? I don't need it for emissions testing.

Heads: As stated trying to stay with 193's (considered Dart 165's and Vortecs) because I think the 193's fit this application best. Any suggestions for mods to these heads that will help them out. Chambers I would clean up and smooth out any sharp blocky edges and may unshroud the valves a little....I do realize that a 400's bore unshrouds the intake valve by it's 4.125 bore (stock)

For the cam, I have a RamJet350/HT383 roller setup with all the required components. The block will be modified to retain use of the lifter OEM retainer. As far as that mod, all I know it has been done to non-roller blocks w/good success...lifter valley tapped and top of the lifter bore machined flat for the retainer.

Fueling. 87-89 octane...hoping. Here is where I would need some help/suggestions. For the TB, I would look at "the ultimate TB mods" bored throttle body (R.V. Morse for example) for increased airflow (keep in mind low RPM goal), OEM intake machined to match TB as needed. Injectors open to suggestions and/or fuel press mods if original 5.7L will flow enough (they will visit Mr. Injector for a rebuild) with using a EP381 fuel pump (?) and adjustable FPR.

Exhaust: Shorty headers or factory manifolds into a Gibson 3" cat back (presently on the truck).

Then will come tuning. I am not up on doing actual tuning myself, willing to learn, but in the interest of time and equipment needed I was wondering is it feasible to have tune done off site (heard bad mojo with TBIChips...so will not go there)? Is this plan to out of reach for a tuner to get pretty close with a tune? Displacement is approx. 16% more, planned rpm range is not high, and camshaft is fairly tame....?

I am sure I am leaving out some important details and can provide info if needed. And again, I any and all suggestions are 100% welcome. I am just in the planning stage as of now. Only parts I have are the block, 193's, and camshaft and roller setup, and shorties. Thanks a lot in advance!