ok, so i have managed to collect 4 different 350's, and i am going to experiment using the parts to see if i can build a 350-400hp 350 out of the stock components (except for cam) that i have collected, and would like your guys' opinions on what combination to run with. (cam suggestions are welcome :D)

1) stock L48 350 from 80z28 (have yet to pull apart, unsure if its 4bolt or 2)
2) mr goodwrench crate 239hp engine (mexican cast higher nickel block) pre '80 style casting with driverside dipstick. and 4blt mains
3) 98 vortec 350 has 906 cast heads in good shape.
4) tbi 350 from early 90's

the pistons from which motor would be the best? my initial thoughts were to go nickel block with vortec heads, vortec pistons, and would be flat tappet cam, but then i got to thinking use the vortec block (roller cam) with the vortec heads, and pistons, and use the crank from the tbi engine as with the larger journals less likely to have bearing issues.


thoughts anybody?

cranks will all have same journal size

2.. enough said 4blt main. bore it .030 over or maybe .060 "let me do some research", throw in a crank out of a 400sbc clearance the block so the crank dont hit. Put in a nice cam, dome top pistons, and deck the heads.

bore it .030 over..

Doesn't the '98 Vortec 350 have the factory hydraulic roller cam and powder metal rods? I've read that those rods are pretty strong for factory rods.

2.. enough said 4blt main. bore it .030 over or maybe .060 "let me do some research", throw in a crank out of a 400sbc clearance the block so the crank dont hit. Put in a nice cam, dome top pistons, and deck the heads.


you must have missed what he wrote completely....he wants to use what he has listed.

I believe you'll find all of those motors have dished pistons (about 12-13cc worth of dish). The pistons in the Vortec motor and probably the early 90s TBI motor, however, use low tension metric rings (not 5/64 and not 1/16). Fresh metric rings will cost you more than the earlier motors that use very common 5/64" rings. Not sure how or if this will help you, but something to keep in mind.

All will have a cast crank, just that the 2 later model motors will be one piece RMS cranks (do you have flexplate/flywheel for all of them so you don't have to buy new??).

TBI motor is likely a roller cam block (no guarantees, however) very similar to the Vortec motor, although it will have a flat tappet cam in it from the factory. As such, you can use the Vortec roller cam gear in it if you want. You just might need to drill and tap for the roller cam lifter valley spider and maybe the roller cam cam retaining plate.

TBI motor uses a standard steel timing cover vs. the plastic cover w/ built-in crank sensor on the Vortec motor, and they interchange with eachother (plus or minus 2 timing cover bolts that aren't used on the Vortec motor's plastic cover).

Crank, rods and other bottom end stuff isn't really much better or worse between the different engines. All cast cranks, all factory forged rods (PM rods in the Vortec may or may not be better than earlier rods, but all of them are better than you need at the 350-400HP level), all cast pistons.

I'd build up the Vortec engine if you can, keeping the factory-style roller cam gear, just with a better camshaft (LT4 "HotCam" is a popular choice at that power level). Obviously, the Vortec heads are the best set of heads of all the motors you've collected. Need to put better springs in them and clearance for a higher lift cam, but the basic castings are certainly capable of 350+ HP with very little work.

If there's anything you can spring for that costs some money it would be boring your chosen block 30-over, getting some flattop pistons in that size (bringing your compression up around 10:1 with 64cc heads) and having the big ends of the rods made truly round again. I've done plenty of cheapie performance builds doing little more than that (plus new oil pump, bearings, gaskets, etc.) and they hold together just fine at those kind of power levels.

have been thinking about this and here is a question. this is probably going to go into my 80 z, 4spd manual, and i would be using the original flywheel and as such, believe i would need to use either of the older style cranks. is that true, or am i misleading myself?

True. One piece RMS cranks take a different flywheel/flexplate- an earlier one from a 2 piece RMS crank won't bolt on (different bolt pattern, etc).

that said, the old crank will fit the newer block correct? not sure what i would need to retro fit it.....

No, it won't. Cranks are different at the rear becuase of the 1 vs. 2 piece RMS.

No real problem, though. Put the good Vortec heads on top of one of the older bottom ends, select an appropriate flat tappet cam (cause that's what the older blocks take) and you can still get to your goals.

Or swipe a flywheel off a junkyard 87-up engine and put it on one of your later bottom ends.

you could get one of these.

http://cgi.ebay.com/ebaymotors/SB-Chevy-Rear-Seal-Adapter-2-Piece_W0QQitemZ110442731103QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item19b6e6565f

you must have missed what he wrote completely....he wants to use what he has listed.
I added a few little things but what i implied was, take his 350 and have it bored .030 over and go to the local junk yard and pull a 400 crank with connecting rods and throw it in the 350 block. Clarence the block and throw in some pistons. Pow you got a 383 stroker! I can get a 400 crank out of a large truck at my local salvage yard for $40. If he has all the basic parts like water pump, alternator, and even his own set of heads then the only real money he is spending is machining the block and a set of pistons and rings.

I added a few little things but what i implied was, take his 350 and have it bored .030 over and go to the local junk yard and pull a 400 crank with connecting rods and throw it in the 350 block. Clarence the block and throw in some pistons. Pow you got a 383 stroker! I can get a 400 crank out of a large truck at my local salvage yard for $40. If he has all the basic parts like water pump, alternator, and even his own set of heads then the only real money he is spending is machining the block and a set of pistons and rings.

good luck stuffing that crank in the 350 block without machining it :)

go to the local junk yard and pull a 400 crank with connecting rods and throw it in the 350 block.
I doubt that's ever done anymore. New cranks are cheaper than trying to machine a junkyard 400 crank.

yeah i do have 400 short block, block is cracked but crank is a-ok. have a set of flat top hyperectics aswell. iron eagle heads also on the shelf. but those pieces are for a different project, the point of this exercise is to create a 350hp powerplant from 350s that i have collected (short of cam and machining the heads to accept bigger cam)

that being said that was a good link to the rear main adapter on ebay, thanks.

i would prefer to use a newer block just for the fact of a roller cam, should use less lift/dur to attain the same power level, but flat tappet doesnt bother me any, just need to run additive's. was thinking for cam size something around .480 lift with .220 duration at least i think thats getting close to maxing out the vortec's without a bunch of machining and watnot.

good luck stuffing that crank in the 350 block without machining it :)
Yeah its gotta be machined, thats the only downfall. Some shops will also charge you an arm and a leg to do it.
With that said, the simple route to take is take the 350 and put in a mild cam, flat/dome to pistons and a nice set of heads and you got a potent 350. Cams and heads will make or brake and engine.

I doubt that's ever done anymore. New cranks are cheaper than trying to machine a junkyard 400 crank.
The 383 crank kits are a good buy so junkyard crawling is no longer needed.

Yeah its gotta be machined, thats the only downfall. Some shops will also charge you an arm and a leg to do it.
With that said, the simple route to take is take the 350 and put in a mild cam, flat/dome to pistons and a nice set of heads and you got a potent 350. Cams and heads will make or brake and engine.

all depends on what the person or customer wants to do....now if i have a customer tell me what he wants and this is his budget i can't go throwing afr heads and all forged internals into a dart block and hand him the bill...

read post number 1 again.... and again and again....:eek: :eek: :eek:

all depends on what the person or customer wants to do....now if i have a customer tell me what he wants and this is his budget i can't go throwing afr heads and all forged internals into a dart block and hand him the bill...

read post number 1 again.... and again and again....:eek: :eek: :eek:
"see if i can build a 350-400hp 350 out of the stock components (except for cam" Now i feel stupid...:crazy:

if you were not so far away i would swap you a lightweight latemodel flywheel for a driveshaft....

use the98 vortec engine and flat top p;istons

get reground roller cam.

That will see you in the 400+ range

^agree. here is a link to a place that will sell you a lt4 hot cam or xe282hr regrind for $120:

http://www.willhoitescams.com

^agree. here is a link to a place that will sell you a lt4 hot cam or xe282hr regrind for $120:

http://www.willhoitescams.com


hey thanks for the Okie link, fellow Okie. I have been wanting to keep some of my money at home vs supporting UPS and Fedex.

Cams Inc was the last I knew of in Okla, and they went to all industrial a long time ago. I fetched a 399(V-16 Cat) camshaft from them here 10 yrs ago or so, and asked them if they still did hotrod stuff and they said hell no, no money in it.

That Willhoites would be down on the river right off I-40, I'll drop in on them some day. See if they grind here or bring it in from Dallas. I have it in my head I went to HS with a Willhoite. A Randall Willhoite. And I want to remember a hotrod associated with that name, but Lord that was a lot of people ago.

hey thanks for the Okie link, fellow Okie. I have been wanting to keep some of my money at home vs supporting UPS and Fedex.

Cams Inc was the last I knew of in Okla, and they went to all industrial a long time ago. I fetched a 399(V-16 Cat) camshaft from them here 10 yrs ago or so, and asked them if they still did hotrod stuff and they said hell no, no money in it.

That Willhoites would be down on the river right off I-40, I'll drop in on them some day. See if they grind here or bring it in from Dallas. I have it in my head I went to HS with a Willhoite. A Randall Willhoite. And I want to remember a hotrod associated with that name, but Lord that was a lot of people ago.

Yeah, actually I stumbled on to willhoites while searching an import message board trying to find some info for a friend. I got the same story you did from cams inc. when I called them about a year ago. maybe they can help me out when I decide on building a pro street earth mover.

If I go ahead with the 383 build I have been threatening to do, im defiantly gonna try their xr282hr knock off.