Sbc 355 swap help

scoti

Royal Smart Person
Supporting Member
Sep 5, 2019
1,691
113
Texas
@ scoti what I'd I want to upgrade the cam
Without knowing the specs of the motor, it's harder to know what cam to choose. Knowing the compression (what pistons & head info), intake/fueling set-up, & what your intended use of the vehicle is normally all has an impact of what cam could be better or worse. Cam manufacturers want to know as much as possible about a combo before making effective & educated suggestions.

The current cam you mentioned is a popular grind. It works fine & sounds good.... that covers the needs of many. But, that same cam in two differently spec'd 350's can or will yield 2 different results.

Lots of stock 'rebuilds' simply use over-sized stock pistons to accommodate boring the cylinder larger to remove the wear. A bigger cylinder w/the same low compression dished-piston & replacement 76cc smog era heads will lack compression. If it has flat-top pistons & some standard GM smog era heads, there's @ least a little more compression to help create some power. Or, if it has those replacement dished pistons but some better flowing aftermarket heads w/smaller chambers, it could end up @ the same compression but the heads better flow numbers increase the power more than just the compression boost alone.

It's a balancing act. There are other factors as well to consider. It's a street car so pump gas right? If so, the cheap/low grade or the highest octane available @ the pump? The higher the compression the more complicated things get to make sure it works as expected.

I'd work on the gearing first & then the converter if it seems to run decent in it's current configuration.
What gear ratio? That depends on tire size, how many street miles vs highway miles it sees, & if track time matters.
 

Mike 86 regal

Not-quite-so-new-guy
Thread starter
Apr 17, 2022
22
1
Oklahoma
Without knowing the specs of the motor, it's harder to know what cam to choose. Knowing the compression (what pistons & head info), intake/fueling set-up, & what your intended use of the vehicle is normally all has an impact of what cam could be better or worse. Cam manufacturers want to know as much as possible about a combo before making effective & educated suggestions.

The current cam you mentioned is a popular grind. It works fine & sounds good.... that covers the needs of many. But, that same cam in two differently spec'd 350's can or will yield 2 different results.

Lots of stock 'rebuilds' simply use over-sized stock pistons to accommodate boring the cylinder larger to remove the wear. A bigger cylinder w/the same low compression dished-piston & replacement 76cc smog era heads will lack compression. If it has flat-top pistons & some standard GM smog era heads, there's @ least a little more compression to help create some power. Or, if it has those replacement dished pistons but some better flowing aftermarket heads w/smaller chambers, it could end up @ the same compression but the heads better flow numbers increase the power more than just the compression boost alone.

It's a balancing act. There are other factors as well to consider. It's a street car so pump gas right? If so, the cheap/low grade or the highest octane available @ the pump? The higher the compression the more complicated things get to make sure it works as expected.

I'd work on the gearing first & then the converter if it seems to run decent in it's current configuration.
What gear ratio? That depends on tire size, how many street miles vs highway miles it sees, & if track time matters.
@ scoti here is the information on the heads, that make sense. It's running like no take off power at all. Pretty much it is toy so it doesn't come out alot. It has the stock gears in it right now. I'm gonna start putting premium in it.
 

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scoti

Royal Smart Person
Supporting Member
Sep 5, 2019
1,691
113
Texas
World Product S/R Torquer's are basic aftermarket replacement iron heads available for the 350ci range sbc with 67 & 76cc chambers. The 'Torquer' version appears to have the larger 2.02 intake size & the regular S/R version is just that (stock replacement 1.94" intake valve head). Based on the description of the pistons as flat-top w/4-valve relief, the compression would likely be better vs a standard smog era 350. The current cam is fine in this instance (not too much & not too little).

A quick google search educated me on the heads.....


Start w/the gears.
 
Last edited:

Mike 86 regal

Not-quite-so-new-guy
Thread starter
Apr 17, 2022
22
1
Oklahoma
World Product S/R Torquer's are basic aftermarket replacement iron heads available for the 350ci range sbc with 67 & 76cc chambers. The 'Torquer' version appears to have the larger 2.02 intake size & the regular S/R version is just that (stock replacement 1.94" intake valve head). Based on the description of the pistons as flat-top w/4-valve relief, the compression would likely be better vs a standard smog era 350. The current cam is fine in this instance (not too much & not too little).

A quick google search educated me on the heads.....


Start w/the gears.
scoti I appreciate it, the guys that been working on it said they can't tune it properly without getting the torque converter
 

85Frankencar

Greasemonkey
May 17, 2010
189
18
Indy
200r4s are great but remember v8 torque curve is much different than a turbo 6. Main parts to watch are input shaft and gear sets. Make sure you set the OD & kickdown cable properly too or you’ll fry your clutch bands. I believe the same goes for 700r4s. One thing too you can swap 700r4 guts into a 200r4. TCI makes a vacuum to electric signal kit for carburetor applications. Check that out. Google Doug Lutes (Mont Carlo SS), he had a great thread on Protouring.com and ran a 200r4 and tracked it. Some good info in there. I’ve got a200r4 in mine too.
 
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